LIBRARY 

OF    THE 

UNIVERSITY  OF  CALIFORNIA. 
Class 


THE  GREAT  WORLD'S  FARM 


THE 

GREAT  WORLD'S  FARM 

SOME  ACCOUNT  OF  NATURE'S  CROPS 
JND  HOW  THET  dRE  GROWN 


BY 

SELINA    GAYE 

Author  of  'The  World? s  Lumber-Room, ,' 
4 Coming,'  etc. 


WITH  A  PREFACE  BY 
G.  S.  BOULGER,  F.L.S.,  F.G.S. 

Professor  of  Botany  &  Otology  in  tht  City  of  London  College 


*  The  world  is  one  vast  garden,  bringing  forth  crops  of  the  most 
luxuriant  and  varied  kind,  century  after  century,  and  millennium 
after  millennium.  Yet  the  face  of  Nature  is  nowhere  furrowed  by 
the  plough,  no  harrow  disintegrates  the  clods,  no  lime  and  phos- 
phates are  strewn  upon  its  fields,  no  visible  tillage  of  the  soil 
improves  the  work  OB  the  great  world's  farm.' 

^&  ifc  PIUUMOND,  "  Tropical  Africa." 


OF  THE 

IVERSiTV    ) 

OF        ..j     J 


UNIVER 

or 


Jork 
THE   MACMILLAN   COMPANY 

LONDON:  MACMILLAN  &  CO.,  LTD. 
I9CO 

[ALL  RIGHTS  RESERVED] 


GENERAL 


PREFACE 
BY  G.  S.  BOULGER,  F.L.S.,  F.G.S. 

Professor  of  Botany  and  Geology  in  the  City  of  London  College. 

IT  cannot  be  too  often  insisted  upon  that  knowledge, 
and  not  ignorance,  is  the  true  parent  of  reverential 
wonder.  Our  appreciation  of  the  beauty  of  a  flower  is 
heightened,  and  not  lessened,  by  the  knowledge  that 
each  curve  in  its  outline  and  each  spot  of  colour  on  its 
petal  has  a  definite  utility  in  the  plant-economy.  Our 
admiration  of  a  landscape  is  intensified,  and  not 
diminished  by  the  thought  that  hill  and  dale  owe  their 
contour  to  the  excavating  power  of  rain  and  rivers 
operating  through  ages  of  time,  and  that  the  vegeta- 
tion which  clothes  them  has  definite  relations  to  the 
composition  of  the  soil  and  to  the  character  of  the 
climate. 

It  has,  therefore,  been  wisely  recognised  by  all  our 
modern  authorities  on  the  subject  of  education,  that 
the  study  of  some  of  the  sciences  should  occupy  an 
early  and  an  important  place  in  our  school  curriculum. 
It  may  be  that  those  universal  favourites,  the  flowers, 
which  can  anywhere  be  readily  obtained,  are  to  be  the 
subject  of  study ;  or  the  innate  love  of  experiment  is 
to  be  fostered  and  directed  in  the  chemical  laboratory; 
or,  perhaps  better  still,  the  physical  features  of  the 
world  around  us,  of  sky  and  sea,  of  mountain  and 
river,  of  crystal  and  pebble,  are  to  be  presented,  not 


vl  Preface 

as  isolated  facts,  but  as  the  offspring  of  constant  and 
universal  law. 

In  the  attempt,  however,  to  employ  the  teaching  of 
science  as  a  means  of  education,  to  develop,  that  is, 
the  innate  mental  faculties  of  a  child,  there  are  several 
dangers  to  which  we  are  exposed :  we  may,  for  instance, 
make  our  subject  so  uninteresting  that  it  becomes  an 
irksome  exercise  of  patience  and  memory,  and  so  loses 
all  its  distinctive  educational  value ;  or,  again,  we  may 
give  much  useful  information,  and  even  teach  valuable 
lessons  of  observation,  accuracy,  and  method,  but  fail 
to  impart  a  sense  of  proportion,  to  show  the  inter- 
dependence of  Nature  as  a  whole,  or  the  relation  of 
our  particular  subject  of  study  to  others  of  equal 
importance. 

Hence  arises  the  great  value  of  books,  such  as  the 
present,  which,  while  simple  enough  to  be  understood 
by  unscientific  readers,  and  so  accurate  as  to  teach 
nothing  that  will  afterwards  have  to  be  unlearnt,  are 
also  extremely  attractive  in  their  selection  and  mar- 
shalling of  facts. 

A  'dry  book'  may  do  much  mischief,  for  it  may 
choke  the  promising  but  tender  seedlings  of  curiosity  ; 
and  if,  as  the  proverb  says,  '  necessity  is  the  mother 
of  invention,'  curiosity  is  certainly  the  mother  of 
knowledge.  Young  people  are  generally  provided  by 
Nature  with  a  plentiful  supply  of  curiosity.  They  may 
yet,  however,  be  very  far  from  learning  the  funda- 
mental methods  of  scientific  inquiry.  Scientific  know- 
ledge, it  has  often  been  explained,  differs  from  other 
knowledge  only  in  being  accurate  and  in  being  syste- 
matic ;  and  neither  of  these  mental  qualities  seems  to 
come  altogether,  like  Dogberry's  reading  and  writing, 
'  by  nature.'  The  lesson  of  how  to  observe,  and  how 
to  discriminate  truth  from  falsehood,  is  one  that  we  all 


Preface  vii 

have  to  learn.  Scientific  observations,  too,  demand 
sustained  attention  and  very  generally  repetition  and 
interpretation  by  such  intellectual  processes  as  com- 
parison and  classification.  The  reasoning  faculties, 
by  which  such  processes  must  be  performed,  require 
the  guidance  of  more  mature  intelligence,  not  only  to 
train  them  but  even  to  bring  them  into  operation  at 
all.  Nor  does  mental  orderliness  come  more  naturally 
than  attention  or  discrimination. 

We  find,  then,  that  we  must  interest,  we  must 
stimulate  the  power  of  observation,  and  we  must  elicit 
and  guide  the  reasoning  faculties.  One  never-failing 
method  of  effecting  these  three  objects  is  to  bring  the 
young  directly  in  contact  with  nature.  To  pick  a 
bunch  of  flowers,  to  chip  fossils  from  the  quarry,  to 
be  shown  some  of  the  more  conspicuous  constellations 
on  a  starry  night,  or  the  moon's  surface  through  a 
telescope,  is  sure  to  arouse  interest,  and  no  competent 
teacher  need  then  fail  to  find  lessons  that  will  not  only 
instruct  or  impart  information,  but  will  also  teach  the 
art  of  reasoning.  So,  too,  though  most  of  the  leading 
truths  of  physical  geography  can  be  illustrated  any- 
where, we  might  wish,  in  order  to  exhibit  to  the  mind 
all  the  facts  upon  which  those  principles  are  based, 
to  take  the  young  student  on  extensive  travels  in 
many  climes  whilst  his  mind  is  still  in  its  most  im- 
pressionable stage.  Failing  this,  nothing  is  so  likely 
to  produce  a  powerful  and  life-like  realization  of  the 
true  facts  of  nature  as  the  word-pictures  of  eye- 
witnesses. For  this  reason  the  writer  of  the  present 
work  seems  to  have  acted  wisely  in  culling,  without 
pretence  of  originality,  from  many  of  the  most  accurate 
works  of  travel  of  modern  times,  and  setting  before  her 
readers  in  detail  the  inferences  to  be  drawn  from  the 
facts  which  she  describes. 


viil  Preface 

Readers  of  more  mature  years  can  hardly  fail  to 
find  in  this  volume  some  facts  that  are  new  to  them, 
some  suggestions  of  a  wider  interpretation  of  nature 
or  of  a  more  accurate  perception  of  its  inter-relations, 
or  some  fresh  cause  for  intelligent  wonder.  If  Newton 
could  look  on  himself  as  a  boy  playing  with  pebbles 
on  the  shore  of  the  great  unexplored  ocean  of  truth, 
every  student  of  nature  may  well  recognise  that,  what- 
ever his  years,  his  experience  or  his  learning,  he  will 
remain  but  a  student,  and  will  never  have  learnt  all 
that  nature  has  to  teach. 

In  looking  upon  nature  as  a  great  farm,  there  is, 
however,  another  and  a  more  important  lesson  than 
any  teaching  of  accuracy  or  of  admiration.  We  read 
of  steam-ploughs,  of  hoeing-machines  and  mechanical 
sowing,  reaping  and  threshing  machines ;  but,  though 
much  labour  may  be  replaced  by  automatic  processes, 
the  controlling  intelligence  of  the  farmer  co-ordinates 
all  the  operations  of  the  farm  to  his  one  end.  It  is 
wisely  said  that 

'  The  undevout  astronomer  is  mad, 

and  Napoleon's  tribute  to  the  Higher  Power,  when  he 
asked  the  sceptical  members  of  his  staff  '  Who  made 
all  these  ?'  is  only  the  natural  testimony  of  intelligence. 
Truly  those  minds  are  to  be  pitied  that  fail  to  see 
more  than  the  blind  operation  of  mechanical  forces 
even  in  the  simplest  of  natural  phenomena ;  but  when 
these  phenomena  are  studied  separately,  there  is 
undoubtedly  a  danger  that  we  may  'fail  to  see  the 
wood  for  the  trees.'  When,  however,  we  contemplate 
the  marvellous  co-ordination  of  all  the  forces  of  nature, 
the  balance  of  vegetable  and  animal  life  and  their 
mutual  dependence,  we  must  be  blind  indeed  if  we 
refuse  to  look  '  thro*  Nature  up  to  Nature's  God.' 


CONTENTS 


PREFACE                ••«•••  V 

I.  INTRODUCTORY  .              .              t              •              •              •  I 

II.  PIONEER-LABOURERS     -              •              c              •              •  1$ 

III.  SOIL-MAKERS      ......  29 

IV.  SOIL-CARRIERS  .              *              •              •              •              •  41 
V.  SOIL-BINDERS      .              .              .              t              •              •  JO 

VI.  FIELD-LABOURERS           •               i              t              •              •  60 

VII.  FIELD-LABOURERS— <*?«/*«««*/«              .              .              •  73 

VIII.  WATER    ...«•••  90 

IX.  DESERTS                •              .              •              •              t              •  105 

X.  ROOTS      .«•••••  124 

XI.  FOOD  FROM  THE  SOIL.              .             .             ,             »  139 

XII.  LEAVES  AND  THEIR  WORK       •              .             .             •  157 

XIII.  CLIMATE                .              t              •              .              •              •  177 

XIV.  BLOSSOM  AND  SEED       .              ,              .              .              .190 
XV.  THE  GOLDEN  RULE  FOR  FLOWERS      .              .              .  2o8 

XVI.  GUESTS  WELCOME  AND  UNWELCOME.              t              t  227 


Contents 


CHAPTER 

XVII.  SEED-SCATTERING  .  .  ,  ,  .  246 

XVIII.  SEED-CARRIERS  .  .  ,  ,  .  ,  ,  26 1 

XIX.  CHANCES  OF  LIFE  r.  •  .  .  «  277 

XX.  FRIENDS  AND  FOES  •  .  ,  .  .».  .  300 

xxi.  NATURE'S  MILITIA  .  •  .  •  .  313 

xxii.  MAN'S  WORK  ON  THE  FARM  •  •  •  •  337 

INDEX        .              ,  ,  ^  ,  .  ,  361 


LIST  OF  ILLUSTRATIONS 


PACK 

FLOWER  VISITED  BY  A  HUMMING  BIRD         -  -  Frontispiece 

SNOWDON  .......       26 

LICHENS  ON  A  ROCK  -          '"*•-"  .  .  .  -       32 

DELTA  AT  THE  HEAD  OF  THE  LAKE  OF  GENEVA    •  46 

MANGROVE  SWAMP        -  -  •  -  .  "54 

THE  GREAT  ANT-BEAR  -  -  -  .  -        88 

BARREL  CACTUS  AND  DESERT  VEGETATION  IN  UTAH  -       98 

DATE  PALM  ON  THE  EDGE  OF  THE  DESERT  -      114 

SUNDEWS,  PITCHER  PLANT,  AND  VENUS'S  FLYTRAP  -      150 

RAFFLESIA  ARNOLDI     -  •  -  -  .  -      194 

WELCOME  GUESTS          -  -  -  .  .  -     2l6 

WINGED  AND   FEATHERED  SEEDS        ....     2$6 

SEYAL  ACACIA  AND  SPINES     -  ....     306 

ASH  STEM  BORED  BY  LARVAE  OF  A  BEETLE  -  -310 

NUTHATCH   FEEDING  HER  YOUNG       -  320 

LONG -EARED  OWL  BRINGING  FIELD-MICE  TO  HER  YOUNG-     334 


The  Great  World's  Farm 


i. 


INTRODUCTORY 

WHAT  would  the  learned  writer  of  the  old  Eton 
geography,  of  sixty  years  ago,  say  to  the  statement  that 
the  whole  earth  is  one  great  farm  or  garden,  almost 
everywhere  covered  with  vegetation,  and  'bringing 
forth  crops  of  the  most  luxuriant  and  varied  kind '  ? 
This  was  certainly  very  far  from  being  his  own  idea ; 
for  he  informed  his  students  that  at  least  one  of  the 
'  quarters '  of  the  world  was  little  more  than  '  a  vast 
sandy  desert/ 

Such  was  his  description  of  the  great  continent  of 
Africa,  where,  according  to  him,  there  was  no  cultiva- 
tion, except  in  the  immediate  neighbourhood  of  a  river 
or  spring,  '  all  the  rest  being  one  wide  tract  of  utter 
desolation  ';  and  he  went  on  to  say:  *  These  cultivated 
places,  appearing  like  islands  or  oases  in  the  great 
desert,  caused  some  of  the  ancients  to  compare  the 
whole  continent  to  a  panther's  skin,  dotted,  as  it  were, 

i 


a      ,  Introductory 

with  spots  of  fertility  surrounded  by  a  brown  and  burning 
desert.' 

As  a  matter  of  fact,  nothing  could  '  more  wildly  mis- 
represent the  truth  '  than  this  description ;  but  it  was 
written  before  the  interior  of  Africa  had  been  explored, 
and  the  old  geographers,  feeling,  it  would  seem,  obliged 
to  say  something,  were  very  much  in  the  habit  of 
writing  'desert'  across  those  regions  of  the  earth  which 
were  to  them  'unknown.' 

These  imaginary  deserts,  which  once  occupied  so 
large  a  space  in  our  maps,  are,  however,  fast  shrinking 
and  dwindling  away  before  the  face  of  the  explorer, 
until  there  are  few,  if  any,  left.  The  last  so-called 
desert  in  America  was  that  to  the  west  of  the  United 
States,  and  that  vanished  some  five-and-twenty  years 
ago,  when  Mr.  Hepworth  Dixon  said  of  it:  'It  has 
retreated  further  and  further,  and  has  taken  its  last 
stand  behind  the  Missouri,  where  I  faced  it,  and  now  I 
can  assure  you  that  I  have  been  right  through  the  Great 
Prairie,  and  desert  there  is  none.  The  prairie  is  the 
pasture-land  of  the  world '  — all  ready  prepared,  that  is, 
to  afford  an  ample  livelihood  to  man's  flocks  and  herds 
as  soon  as  he  should  choose  to  make  use  of  it;  and 
certainly,  therefore,  no  desert,  though  '  only  an  Indian 
hunting-ground ' ! 

But  still,  it  may  be  said,  there  is  a  wide  difference 
between  a  desert  and  a  farm.  If  the  prairie  is  not 
bare,  at  least  it  is  uncultivated ;  and  the  word  '  farm ' 
suggests  the  idea  of  ploughs  and  harrows,  orderly 
crops,  sheep  and  cattle.  Very  true ;  but  because 
nature  farms  in  ways  of  her  own,  on  a  large  scale  and 
without  fuss,  while  man  farms  in  his  way  on  a  small 
pne,  and  lets  all  the  world  know  what  he  is  doing,  is 


Introductory  3 

that  any  reason  for  denying  to  nature  the  name  of 
'farmer'? 

How  much  of  the  earth  has  man  brought  under 
cultivation  ?  In  Europe,  where  he  has  done  most,  the 
proportion  varies  from  little  more  than  a  twentieth  (in 
Sweden),  to  a  little  more  than  one-half  (in  Belgium). 
Supposing  that  he  farms,  or  '  improves/  one-tenth  of 
the  land  all  the  world  over — and  he  certainly  does  not 
do  more  at  present — what  becomes  of  the  other  nine- 
tenths  ?  It  is  not  a  desert,  it  does  not  lie  idle ;  with 
but  few  exceptions,  indeed,  it  is  covered  with  crops  of 
one  sort  or  another ;  for  the  world  is  a  green  world, 
not  a  brown  one. 

But,  where  crops  are  grown  century  after  century, 
millennium  after  millennium,  no  matter  whether  they 
be  wild  or  not,  there  must  needs  be  tillage,  and 
that  of  the  most  thorough  kind,  fully  deserving 
the  name  of  farming,  though  it  may  be  carried  on 
without  steel  ploughs,  and  so  quietly  as  to  escape  our 
notice. 

There  are  vast  pasture-lands  here,  there  are  exten- 
sive forests  there ;  there  are  woods,  jungles,  heaths, 
moors,  downs,  but  they  have  all  been  planted ;  and 
the  soil  was  prepared  in  the  first  instance,  and 
has  been  renewed  since,  by  labourers  who  are  not 
less  truly  deserving  of  the  name  of  labourer  than 
the  ploughman,  though  they  do  not  work  with  his 
implements. 

When  Captain,  afterwards  Sir  Francis,  Head, 
travelled  900  miles  across  the  Pampas,  he  saw  to  his 
surprise,  first,  180  miles  of  the  most  luxuriant  clover 
and  wild  artichokes ;  then  an  unbroken  stretch  of  long 
grass,  450  miles  wide,  without  a  weed;  and  finally, 


4  Introductory 

growing  up  to  the  base  of  the  Cordillera,  a  grove  of 
low  trees  and  shrubs. 

Man  had  had  no  hand  in  preparing  the  soil  for  this 
grass  and  clover,  man  had  neither  sown  them  nor 
cared  for  them  in  anyway;  yet  there  they  were,  just 
as  good  food  for  his  cattle  as  if  they  had  been  grown 
on  the  most  orderly  of  human  farms.  Surely,  then, 
the  lands  of  the  Pampas  had  been  'farmed'  most 
successfully,  by  one  means  or  another.  For  the 
word  '  farm  '  is  said  to  be  derived  from  an  Anglo- 
Saxon  verb  which  means  '  to  supply  with  food/  and 
certainly,  in  this  sense,  the  lands  which  man  still 
leaves  to  nature's  labourers  have  every  claim  to  be 
considered  as  one  vast  farm ;  for  they  grow,  many 
of  them,  the  most  luxuriant  crops,  and  they  feed  more 
live-stock  than  can  be  numbered. 

Man  grows  for  himself  and  his  live-stock  a  few 
vegetables — about  two  hundred  and  fifty  species — and 
he  has  adopted,  and  partly  domesticated,  about  two 
hundred  animals.  But  on  the  great  natural  farm 
things  are  done  on  a  very  much  grander  scale.  Here 
the  species  of  crops  grown  number  not  much  less 
than  a  hundred  and  forty  thousand;  and  the  different 
species  of  live-stock  amount  to  some  millions. 

With  so  many  animals  to  feed,  and  so  many  crops 
to  grow,  nature's  farm  -  labourers  do  not  allow  of 
'  deserts ' ;  and  wherever  there  is  an  unoccupied 
surface,  they  hasten  to  take  possession,  and  if  possible 
sow  something  upon  it,  if  it  be  but  a  lichen.  They 
sow  even  the  little  heaps  of  dust  which  collect  itt 
sheltered  nooks,  on  the  leads  of  the  church-tower,  on 
walls,  in  the  angles  of  masonry,  and  make  them  bear 
at  least  a  blade  or  two  of  grass,  and  often  quite  a  crop 


Introductory  5 

of  various  green  things.  Generally  speaking,  it  is  only 
by  recent  lava-fields,  and  the  loftiest,  bleakest  peaks  of 
rock,  that  these  energetic  labourers  are  baffled,  and 
then  it  is  only  for  a  time. 

Over  and  over  again,  as  Mr.  Ball  says,  he  was  told 
in  different  parts  of  the  world  that  such  and  such  a 
spot  was  entirely  devoid  of  vegetation,  or,  in  other 
words,  a  desert,  and  over  and  over  again  he  found  it  to 
be  quite  a  mistake.  On  the  so-called  '  bare '  peaks  of 
the  Dolomite  Mountains  he  always  found  a  'fair 
number '  of  plants  hidden  in  cracks  and  crevices ;  even 
at  Suez,  on  the  exposed,  burnt-up  face  of  the  mountain 
Djebel  Attakah,  he  still  found  something,  and  in  the 
northern  part  of  the  great  Sahara,  though  vegetation 
was  scanty,  it  was  difficult  to  find  many  yards  together 
that  were  actually  bare. 

In  fact,  Mr.  Ball  had  come  to  doubt  the  existence  of 
'deserts'  altogether  by  the  time  he  reached  the 
'  rainless  zone '  of  Peru,  and  was  once  more  told  that 
he  would  find  no  vegetation  at  all.  Certainly  this  was 
more  barren  than  any  part  of  the  world  which  he  had 
seen  yet,  except  indeed  the  drifting  sands  above  Cairo ; 
yet  even  here  there  were  plants,  stunted  bushes  in  the 
gullies,  and  tiny  vegetables  in  the  depressions  where 
the  scanty  rain  rests  longest ;  but  they  wanted  looking 
for,  as  there  was  scarcely  one  so  much  as  three  inches 
high.  The  labourers  had  done  their  best ;  they  had 
prepared  the  soil,  and  they  had  sown,  but  they  had 
been  hindered  from  growing  anything  like  a  luxuriant 
crop  by  want  of  water.  And  at  one  place,  Tocopilla, 
they  had  been  entirely  baffled;  for  here  at  last  Mr. 
Ball  found  his  desert  —  an  altogether  barren  spot 
where  not  a  single  green  thing  was  to  be  seen,  and 


6  Introductory 

not  so  much  as  a  lichen  was  to  be  discovered,  even 
with  the  help  of  a  microscope. 

But  this  is  quite  an  exceptional  state  of  things,  due 
to  the  extreme  rarity  of  the  rain;  and  such  utterly 
barren  surfaces  are  not  only  very  few,  but  very  small 
compared  with  the  whole  extent  of  the  farm-— mere 
spots,  in  fact,  in  the  midst  of  generally  luxuriant 
crops. 

In  most  cases  the  so-called  deserts  are  deserts 
only  for  want  of  water;  the  soil  has  been  carefully 
made  ready,  and  in  the  Great  Sahara  and  the  deserts 
of  Egypt  it  is  extremely  rich,  though  at  present  covered 
with  sand.  What  it  might  be,  and  how  easily  it  might 
be  made  to  '  blossom  like  the  rose,'  we  can  to  some 
extent  guess,  when  we  find  that  the  passing  showers, 
which  are  all  that  visit  the  deserts  of  Egypt,  are 
sufficient,  scanty  as  they  are,  to  awaken  'the  green 
things  on  the  yellow  surface ' ;  though  we  may  well 
wonder  how  the  seeds  '  could  germinate  after  months 
of  exposure  to  the  burning  sun/ 

And  then,  again,  while  it  is  quite  certain  that 
such  vegetation  as  exists  in  these  regions  is  grown 
entirely  by  the  natural  labourers,  there  seems  also 
good  reason  to  suppose  that  man  actually  does  much 
to  hinder  their  work. 

If,  for  instance,  man  and  his  domestic  animals  were 
banished  from  the  Arabian  and  African  deserts,  it  is 
believed  by  Mr.  Marsh  that  many  parts  of  them  would 
soon  be  covered  with  forests,  and  with  forests  would 
come  rain,  to  the  enormous  benefit  of  the  whole  region. 
Acacias  of  several  species  are  constantly  being  sown, 
and  they  sprout  up  plentifully  around  the  springs  and 
winter  water-courses,  while  grasses  and  shrubs  grow 


Introductory  y 

up  under  their  sheltering  shade.  But  these  latter  are 
mown  down  as  fast  as  they  grow  by  the  hungry  cattle 
of  the  Arabs ;  and  even  the  trees  do  not  escape,  for 
the  goat  devours  the  seedlings  whenever  it  has  the 
opportunity,  and  the  camel  will  bite  through  thorny 
branches  as  thick  as  the  finger,  and  unfortunately  it 
has  a  particular  liking  for  the  twigs,  leaves  and  seed- 
pods  of  the  Acacia ;  so  that  between  them,  the  tree  of 
the  desert  has  but  little  chance.  If  only  they  were  left 
undisturbed  for  a  few  years  these  spots  would  be 
covered  with  groves,  which  would  gradually  extend 
where  now  little  can  grow  but  the  foxglove  and 
colocynth. 

Still,  even  now,  these  deserts  cannot  be  called  bare, 
though  their  crops  are  scanty.  As  we  have  said  before, 
the  labourers  on  the  great  farm  do  not  allow  any 
surface  to  be  bare,  if  they  can  help  it,  and  they  work 
as  if  it  were  their  one  object  to  grow  as  many  crops  as 
possible.  The  very  snow-fields  and  ice-fields  are  not 
allowed  to  lie  idle,  for  there  is  soil  even  here,  and  it 
must  not  be  wasted. 

Dust,  meteoric  dust  from  the  higher  regions  beyond 
our  atmosphere,  is  constantly  falling  all  over  the  earth, 
to  the  amount,  it  is  believed,  of  more  than  500,000  tons 
every  year;  and  though,  being  scattered  evenly  over 
the  whole  surface,  it  must  be  spread  very  thin  indeed ; 
still,  where  there  is  no  other  mineral  matter,  as  on  the 
snow  and  ice-fields  of  the  Arctic  regions,  it  is  quite 
perceptible,  and  it  is  enough  for  the  growth  of  such 
humble  vegetables  as  the  *  Red  Snow,'  which  in 
summer  covers  the  white  surface  with  a  flush  of  rose- 
colour  many  miles  in  extent.  Nor  are  this  and  other 
similar  minute  plants  grown  to  no  purpose.  These 


8  Introductory 

'  barren  fields '  are  also  part  of  the  great  world's  farm, 
an  outlying  part,  it  is  true,  where  the  produce  is  not 
large:  but,  such  as  they  are,  the  crops  are  needed, 
for  there  are  glacier-fleas  and  other  live-stock  even 
here,  and  these  tiny  vegetables  supply  them  with 
food. 

Nature's  labourers  are  such  zealous  and  thrifty  hus- 
bandmen that  they  are  always  on  the  watch  to  occupy 
every  inch  of  space  where  anything  can  be  grown  the 
moment  it  is  vacated,  and  even  before.  They  will 
overrun  our  gravel  paths,  and  grow  grass  in  our  streets 
if  allowed,  and  they  will  take  but  a  very  short  time 
to  convert  the  most  highly  cultivated  garden  into  a 
wilderness  without  any  trace  of  a  path  in  it,  if  it  be 
given  up  to  them.  This  is  true  even  in  such  temperate 
climates  as  our  own,  but  in  warmer  latitudes  the 
incessant  struggle  of  the  wild  crops  to  invade  and 
recover  the  ground  which  they  have  lost  is  still  more 
marked. 

At  Pard,  in  Brazil,  for  instance,  we  are  told  that 
every  lane,  yard,  and  square  is  a  battle-ground.  Even 
the  roofs  and  cornices  of  some  of  the  public  buildings 
are  occupied  by  plants  or  small  trees,  which  wave  their 
feathery  heads  aloft  like  flags  of  triumph  in  defiance  of 
the  enemy.  The  city  is  hemmed  in  by  a  wall  of  tropical 
forest,  consisting  of  giant  trees,  palms,  and  tangled 
creepers,  which  ever  and  anon  send  out  skirmishers  to 
try  and  effect  a  lodgment  in  the  enemy's  territory  ;  and 
so  well  do  they  succeed  where  circumstances  favour 
them,  that  a  large  square,  which  was  cleared  and  turfed, 
but  left  unguarded,  was  covered  in  five  years'  time  with 
a  tangled  mass  of  vegetation  fifteen  feet  high,  and 
denser  than  the  virgin  forest. 


Introductory  <) 

For  there  is  no  lack  of  labourers  on  the  great  rarm. 
They  are  employed  by  the  million  in  all  parts  of  it,  an  • 
though  they  are  always  ready  to  reclaim  any  portion 
which  has  been  taken  from  them,  they  nevertheless 
attend  impartially  to  the  whole  —the  small  part  which 
man  has  taken  under  his  own  care,  as  well  as  that 
which  he  leaves  at  present  entirely  to  their  manage- 
ment. 

And  a  very  sorry  condition  the  human  farmer's  fields 
would  be  in  if  they  were  left  to  himself  alone,  in  spite 
of  all  his  improved  modern  appliances  and  scientific 
knowledge. 

'  It  is  an  e  sy  error  to  consider  that  he  who  has  tilled 
the  ground  and  sown  the  seed  is  the  author  of  his  crop.' 
And  for  the  most  part,  perhaps,  the  farmer  realizes  but 
little  of  the  vast  debt  which  he  owes  to  the  unseen, 
unnoticed,  and  often  abused  labourers,  who  are  inces1* 
santly  at  work  for  him. 

Of  course,  he  knows  very  well  that  he  cannot  do 
without  sun  and  rain,  and  he  will  readily  allow  that 
dew,  frost  and  wind  are  useful,  and  that  at  present  he 
could  hardly  do  without  them ;  but  grant  him  these — 
and  what  are  they  after  all  but  labourers  borrowed 
from  the  larger  farm — and  surely  his  improved  ploughs 
and  harrows,  and  his  patent  manures,  will  be  able 
to  manage  the  rest.  In  the  days  when  a  forked 
stick  was  the  best  plough,  no  doubt  things  were 
different,  and  the  farmer  was  more  dependent  upon 
what  the  natural  labourers  were  pleased  to  do  for  him, 
but  now  ! 

Well,  let  him  try !  There  is  an  island  just  risen 
above  the  waves  here,  or  there  is  a  stream  of  cooled 
lava  there — nice,  fresh,  virgin  surfaces  both  of  them, 


i  o  Introductory 

where  nature's  husbandmen  have  not  yet  been  at  work, 
so  that  he  may  keep  either  to  himself,  and  show  what 
he  can  do  when  he  is  not  interfered  with.  Let  him 
try  his  modern  steel  plough,  driven  by  steam,  too,  if 
he  will,  upon  either  of  these. 

But  there  is  no  soil !  Of  course  not ;  is  the  soil  put 
ready  for  nature's  labourers  ?  Do  they  not  have  to 
make  it,  and  out  of  these,  or  similar  materials  ?  But 
one  cannot  plough  the  bare  rock,  even  with  the  help  of 
steel  and  steam ;  and  before  these  can  do  anything 
with  it,  it  must  be  broken  up  and  crumbled  by  other 
workers,  much  more  humble  and  feeble  in  appearance, 
most  of  them  absolutely  noiseless,  Some  quite  invisible, 
and  yet — far  more  powerful. 

Wonderful  things,  no  doubt,  are  being  done  with 
machinery,  and  the  time  may  possibly  come  when  we 
shall  be  able  to  grind  up  the  rock  without  too  great 
expenditure  of  time  and  labour ;  but  even  then, 
powdered  rock  is  not  soil,  and  will  not  grow  any 
crop  worthy  of  the  name.  It  must  be  mixed  as 
well  as  pounded  before  it  can  be  converted  into 
fertile  soil,  such  as  the  farmer  will  find  it  worth 
his  while  to  cultivate.  And  who  is  to  mix  it  ?  It 
.  will  not  pay  him  to  attempt  the  work  himself 
on  any  large  scale ;  but  it  has  been  done,  and  is 
constantly  being  done,  on  all  parts  of  the  great  natural 
farm. 

On  the  whole,  then,  the  farmer  will  probably  find  it 
best,  at  least  for  the  present,  to  accept  what  has  been 
done  for  him,  and  to  cultivate  the  soil  which  he  finds 
ready  made. 

*  Ready  made  ?'  but  doesn't  he  still  have  to  plough 


Introductory  \  i 

it,  and  harrow  it,  and  manure  it  ?  To  be  sure ;  but 
this  is  no  more  than  has  to  be  done,  and  is  done,  by 
the  natural  husbandmen  also  all  the  world  over.  Crops 
cannot  be  grown  year  after  year,  for  many  years  in 
succession,  without  constant  labour.  For  every  crop 
takes  something  from  the  soil,  and  the  loss  has  to  be 
made  good.  The  clods  must  be  broken  up,  too,  or  the 
air  and  rain  cannot  enter  freely,  and  the  roots  cannot 
make  their  way  through  the  soil.  And  this  the  farmer 
must  do  as  best  he  can,  with  his  plough  and  harrow ; 
but  these  are  at  best  only  clumsy  instruments,  and  they 
are  not  enough  by  themselves.  If  the  fields  were 
deserted  by  the  'natural  ploughmen,'  the  worms  and 
others,  the  farmer  would  speedily  find  that  his  ploughs 
could  accomplish  only  the  rough  part  of  the  work. 
And  it  is  much  the  same  with  the  harrows ;  they  can- 
not do  the  fine  work  of  the  great  '  natural  harrowi'  the 
frost,  which  crumbles  the  soil  grain  by  grain  y  till  it  is 
reduced  to  the  condition  of  dust  and  ashes,  ready  for 
sowing. 

And  now  surely  the  farmer  may  put  in  his  seed  and 
feel  that  if  only  seasonable  weather  be  granted  him 
he  may  be  quite  independent  of  further  help  from  his 
humble  fellow -labourers.  The  'if,'  to  be  sure,  is 
rather  a  great  and  important  '  if,'  and  altogether 
beyond  his  own  control;  but,  granted  the  weather, 
may  he  not  go  on  and  prosper  ? 

Not  unless  he  is  prepared  to  pay  a  whole  army  of 
boys  to  keep  off  marauders ;  and  even  then  he  would 
probably  find  himself  worsted  in  the  battle  with  slugs, 
and  snails,  and  grubs,  for  these  creatures  have  an 
especial  fondness  for  seedlings,  wild  and  cultivated. 


1$  Introductory 

We  are  told,  for  instance,  by  the  Rev.  F.  Morns,  that 
out  of  504  grains  of  rape  planted  as  an  experiment, 
200  were  eaten  or  injured.  And  how  many  even  of 
these  would  have  escaped  if  '  nature's  militia,'  the 
army  of  birds,  had  withdrawn  their  services  ?  Very 
few,  probably,  for  the  farmer  has  not  yet  invented  any 
satisfactory  substitute,  and  if  he  be  wise  he  will  cer- 
tainly welcome  them  in  his  fields,  and  be  glad  that 
they  do  not  limit  their  care  to  the  wild  crops  of  the 
farm. 

But  when  the  crop  has  escaped  these  serious 
perils  and  dangers,  what  then  ?  Even  then  the 
farmer  will  not  in  many  cases  have  any  harvest, 
unless  nature  again  comes  to  his  help  and  lends  him  a 
fresh  set  of  workers  different  from  any  hitherto  em- 
ployed in  his  service.  This  is  especially  true  of  the 
fruit-farmer  and  the  market-gardener.  The  orchards 
and  gardens  may  be  a  mass  of  blossom,  but  if  they 
are  left  to  themselves  at  this  critical  time  there  will  be 
few  apples,  strawberries  or  raspberries,  and  absolutely 
no  melons  or  cucumbers,  no  matter  how  favourable  the 
weather  may  be.  And  the  same  holds  good  with 
regard  to  many  another  crop.  Help  is  needed  if  they 
are  to  bring  their  fruit  to  maturity,  and  this  help  the 
grower  is,  generally  speaking,  quite  unable  to  give. 
That  is  to  say,  he  may  be  able  to  give  it  here  and  there 
in  a  few  instances,  but  he  would  be  powerless  in  an 
orchard,  and  would  not  be  able  to  afford  the  time 
necessary  to  do  the  delicate  work  required  in  a  single 
strawberry  bed.  Again,  therefore,  he  must  look  to 
Nature's  labourers  for  assistance. 

Take  the  following  example,  for  instance:    In  his 


Introductory  1 3 

garden  at  Santo  Domingo,  Nicaragua,  Mr.  Belt,  the 
naturalist,  sowed  some  scarlet-runner  beans.  The  soil 
was  good,  and  the  climate  was  favourable  to  bean-life, 
and  the  scarlet-runners  grew  and  flourished,  and  finally 
blossomed  abundantly. 

But  it  was  finally!  for  here  their  career  ended. 
They  did  not  produce  a  single  bean  among  them, 
simply  because  the  right  labourers  were  not  at  hand  to 
give  the  requisite  help. 

The  garden  in  which  the  beans  grew  had  been 
recently  taken  from  the  forest,  by  which  it  was  still 
surrounded ;  and  that  the  labourers  in  this  part  of  the 
farm  were  not  idle  was  quite  evident  from  the  abundant 
luxuriance  of  the  vegetation.  But  it  was  tropical 
vegetation,  and  as  it  did  not  include  scarlet-runners, 
these  were  in  the  position  of  foreigners,  whose  appeals 
for  assistance  were  not  understood.  It  was  in  vain 
they  put  forth  the  bright  flowers,  which  were  well- 
known  signals  in  their  native  land,  and  would  there 
have  brought  them  the  helpers  they  needed — no  one 
noticed  them.  They  were  made  welcome  to  the  soil, 
the  rain  and  the  sunshine,  and  then  they  were  left  to 
themselves  and  their  master,  with  the  result  already 
mentioned — no  fruit ! 

And  who  were  the  gardeners  whose  absence  proved 
to  be  of  such  vital  importance  ?  Humble  bees,  only 
humble  bees!  and,  indeed,  only  the  particular  species 
of  humble  bees  which  wait  upon  scarlet-runners. 
There  were  plenty  of  others,  but  they  did  not  under- 
stand, though  very  probably  they  would  have  come 
to  do  so  in  the  course  of  a  few  seasons.  As  it  was, 
however,  failing  these  insect  labourers,  there  was 


14  Introductory 

nothing  to  be  done — nothing  to  take  their  place. 
Man  has  not  yet  discovered  any  substitute  for  the 
bee. 

In  the  following  chapters  we  shall  consider  in  more 
detail  the  various  ways  and  means  by  which  the  work 
of  the  great  farm  is  carried  on  by  the  natural  labourers, 
and  also  some  of  the  changes  made  in  it  by  the  work 
and  unconscious  influence  of  man. 


II. 

PIONEER  LABOURERS 

No  one  needs  to  be  told  that  all  living  things  require 
food  of  one  sort  or  another  to  keep  them  alive;  but 
some  people  have  fancied,  even  within  the  last  hundred 
years,  that  vegetables  had  such  delicate  appetites  as  to 
need  nothing  but  air  and  pure  water  for  their  susten- 
ance. 

If  this  were  so,  then,  of  course,  one  sort  of  soil 
would  agree  with  them  as  well  as  another;  and,  in 
fact,  it  would  not  be  wanted  at  all  except  as  a  protec- 
tion to  their  roots,  and  as  a  means  of  fixing  them  to 
one  spot  and  enabling  them  to  stand  against  the  wind. 

As  a  matter  of  fact,  however,  no  vegetables  live  upon 
a  diet  of  mere  air  and  water. 

But  then,  what  of  the  seaweeds  which  float  about  in 
the  ocean  ?  Are  there  not  vast  meadows  of  weed  far 
away  from  soil  or  even  rocks  of  any  kind  ?  Does  not 
the  ocean,  moreover,  swarm  everywhere,  from  the 
Polar  regions  to  the  Equator,  with  microscopic  vege- 
tables ?  and  is  it  not  a  fact  that  no  seaweeds,  not  even 
those  which  cling  to  the  rocks,  receive  any  of  their 
nourishment  through  their  roots,  and  therefore  must 
live  upon  water  ? 


1 6  Pioneer  Labourers 

Quite  true  that  they  do  not  feed  by  means  of  their 
roots — indeed,  no  seaweeds  possess  true  roots ;  and  it 
is  quite  true,  also,  that  they  live  upon  what  they  obtain 
from  the  water,  but  surely  the  taste  of  it  is  sufficient  to 
prove  that  it  is  not  mere  water. 

There  is  no  such  thing  as  pure,  absolutely  pure, 
water  in  nature ;  and  sea-water,  which  is  much  heavier 
than  fresh  water,  contains  thirty-five  parts  of  solid 
matter  in  every  thousand.  The  rivers  are  constantly 
pouring  into  it  small  quantities  of  every  sort  of  mineral 
substance  that  can  be  dissolved,  while  the  sun  draws 
up  from  it  almost  pure  water,  leaving  the  salts  behind 
to  accumulate  and  help  to  feed  the  crops  of  seaweed, 
besides  providing  material  for  the  skeletons  of  corals 
and  sponges  and  the  shells  and  bones  of  other  sea- 
creatures. 

All  plants,  then — whether  they  tower  aloft  like  the 
giants  of  the  tropical  forest,  or  send  out  streamers  two 
or  three  hundred  feet  in  length  like  the  Giant  Kelp  of 
the  Atlantic  Ocean  ;  whether  they  are  so  minute  as  to 
be  altogether  invisible  to  the  naked  eye,  and  whether 
they  live  in  earth  or  in  water — are  alike  in  this,  that 
they  live  upon  other  food  besides  mere  air  and 
water. 

We  may  easily  satisfy  ourselves  of  this  by  burning  a 
bit  of  wood,  a  few  grains  of  corn,  or  any  other  vege- 
table matter.  When  it  has  burnt  as  long  as  there  is 
anything  to  burn,  and  ail  the  gases  and  water  it  con- 
tained are  driven  away,  a  small  quantity  of  ash  will 
remain,  consisting  of  salts,  or  compounds  of  various 
metals.  The  whole  amount  is  usually  very  small — so 
small  that  we  might  perhaps  be  disposed  to  think  it 
could  not  be  of  any  very  great  consequence. 


Pioneer  Labourers  17 

If,  for  instance,  we  were  to  burn  a  hundred  grains  of 
wheat  so  thoroughly  that  nothing  but  ash  remained, 
we  should  find  the  whole  amount  of  this  to  be  equal  to 
about  two  of  the  grains,  or  less  ;  while  if  we  were  to 
take  peas  or  beans,  the  amount  in  a  hundred  of  each 
would  be  equal  to  less  than  three  peas,  and  less  than 
four  beans. 

There  would  be  more  in  the  straw  or  stems  of  all 
three  kinds  of  plants,  but  still  the  quantity  appears  so 
small  that  one  might  doubt  its  being  absolutely  essential 
if  one  did  not  know  that  it  was  so. 

However,  '  many  a  mickle  makes  a  muckle,'  and 
when  we  consider,  not  single  plants  or  a  handful  of 
grain,  but  a  whole  crop,  the  amount  of  mineral  matter 
becomes  large  enough  to  look  important.  Thus,  while 
a  pinch  or  two  of  dust  might  represent  the  entire 
amount  of  ash  of  all  sorts  in  a  single  turnip  or  carrot, 
there  are,  on  an  average,  about  40  pounds  of  lime  alone 
in  22  tons  of  turnips,  more  in  proportion  in  the  carrots, 
and  very  much  more  in  an  equal  weight  of  clover. 

The  mineral  substances  chiefly  taken  up  by  plants 
are  sulphur,  phosphorus,  silica,  potash,  soda,  lime,  iron, 
magnesia,  manganese,  together  with  mineral  compounds 
of  the  two  gases  chlorine  and  fluorine.  All  these  are 
contained  in  the  rocks ;  but  the  question  is,  How  are 
they  to  be  made  available — how  is  the  plant  to  get 
hold  of  them  ?  There  is  abundance  of  food,  but  as 
long  as  it  is  stored  in  the  rocks  it  might  as  well  be 
locked  up  so  far  as  most  of  them  are  concerned,  for 
they  cannot  get  at  it  or  make  use  of  it.  Of  course,  we 
all  know  that  seeds  cannot  grow,  though  they  may 
sprout,  upon  a  slab  of  bare  stone,  even  though  it  may 
be  rich  in  the  very  food  they  want.  The  stone  must  be 

2 


1 8  Pioneer  Labourers 

converted  into  soil  before  they  can  turn  it  to  account ; 
and  how  is  this  to  be  accomplished  ? 

If  man  had  to  make  his  soil  from  the  rocks  before 
he  could  grow  his  crops,  he  would  have  to  begin  with 
crowbars  and  pickaxes,  if  he  did  not  first  resort  to 
blasting  with  gunpowder  or  dynamite,  and  even  then 
his  progress  would  be  slow  and  laborious. 

Nature  usually  works  in  a  much  more  quiet  and  un- 
obtrusive fashion,  but  there  are  times  when  she,  too, 
has  recourse  to  blasting  as  a  preliminary  measure.  She 
mines  the  rocks  and  shatters  them  by  means  of  the 
earthquake,  compared  with  which  the  power  even  of 
dynamite  is  insignificant ;  and  if  these  rough  measures 
do  but  little  towards  preparing  the  soil,  they  unques- 
tionably make  things  easier  for  the  army  of  labourers 
who  follow. 

But  it  is  the  noiseless  and  often  invisible  workers 
who  accomplish  most,  for  they  are  at  work,  some  or 
other  of  them,  incessantly  during  every  moment  of 
every  hour,  day  and  night,  summer  and  winter,  through- 
out the  whole  year. 

Usually  the  first  of  the  silent  labourers  to  begin  work 
upon  the  rocks  are  also  the  invisible  ones — the  gases  of 
air  and  water,  which  wear  away  the  very  hardest  rocks 
by  degrees.  They  are  not  able  to  work  equally  fast 
upon  all  rocks,  but  where  they  can  be  employed,  there 
the  work  goes  on  most  rapidly.  Those  rocks  which  are 
best  able  to  resist  them  decay  more  slowly,  even  though 
they  be  actually  softer  and  yield  more  readily  to  such 
labourers  as  wind  and  rain.  In  other  words,  the  un- 
seen chemical  workers  produce  more  effect  on  the  rocks 
than  do  the  seen,  mechanical  workers. 

The  two  gases  which  do  the  chief  part  of  the  chemical 


Pioneer  Labourers  19 

work  are  oxygen  and  carbon  dioxide,  formerly  called 
carbonic  acid.  Rocks  containing  much  iron  are  espe- 
cially open  to  the  attacks  of  the  one,  and  those  con- 
taining lime,  potash,  soda,  to  the  attacks  of  the  other. 
We  are  all  familiar  with  the  fact  that  iron  and  steel 
become  covered  with  rust  if  left  exposed  to  the  air. 
Keys  rust  if  left  in  their  locks,  and  even  polished  fire- 
irons  often  rust  in  the  summer,  unless  they  are  oiled  or 
greased  and  so  protected  from  the  air.  What  happens 
in  these  cases  is  that  the  oxygen,  always  present  both 
in  the  air  itself  and  in  the  watery  vapour  floating  in  the 
air,  lays  hold  of  the  metal  and  combines  with  it  to  form 
a  compound  substance — an  oxide — which  is  looser  and 
softer,  and  takes  up  more  room  than  the  metal  alone. 
At  first  the  rust  is  a  mere  reddish-brown  stain  ;  but  as 
the  oxygen  eats  deeper  and  deeper,  and  more  and  more 
oxide  is  formed,  it  swells  up  unevenly  abovf  the  sur- 
rounding surface,  and  feels  rough  to  the  touch.  It  is  so 
soft  that  it  may  be  partly  rubbed  off  by  the  finger,  and 
when  the  rust  is  cleaned  away  there  will  be  scars  and 
indentations  left,  showing  how  much  of  the  metal  has 
been  removed. 

Now  it  would  take  a  much  harder  blow  to  break  a 
piece  of  iron  than  it  would  to  shatter  a  flint ;  but  if  the 
two  were  left  exposed  to  the  air,  the  metal  would  waste 
away  long  before  any  impression  was  made  on  the  stone. 

Very  many  rocks  contain  iron,  as,  for  instance,  the 
slates,  sandstones,  granites,  and  basalts,  some  more, 
some  less,  but  hardly  ever  in  a  pure  state.  The  basalt 
of  the  Giant's  Causeway  contains  so  much  iron  that, 
on  those  sides  which  are  most  exposed  to  the  weather, 
it  not  only  looks  rusty,  but  is  also  softer  on  the  surface 
and  less  compact  within,  for  nature's  labourers  do  not 


so  Pioneer  Labourers 

generally  work  singly  and  alone,  but  in  union  one  with 
the  other,  and  the  great  ally  of  oxygen  is  moisture. 

Let  us  take  basalt  as  an  example,  and  see  how  this 
rock  is  crumbled  into  soil.  In  perfectly  dry  air,  at  the 
ordinary  temperature,  oxygen  is  powerless  to  do  even 
so  much  as  tarnish  iron  in  the  mass,  though  it  would 
have  no  difficulty  in  reducing  it  all  to  oxide — that  is, 
rust — if  the  same  mass  of  iron  were  exposed  to  its 
action  in  the  form  of  powder.  Fireirons  do  not  rust 
in  winter,  or  when  in  constant  use,  because  the  fire 
keeps  them  dry ;  they  do  rust  when  unused  in  summer, 
because  natural  air  is  never  perfectly  dry,  even  on 
the  driest  summer  day,  not  even  in  the  midst  of  the 
parching  desert. 

But,  if  iron  quickly  rusts  when  exposed  to  the  damp 
air  of  such  a  climate  as  ours,  we  all  know  how  much 
faster  it  does  so  when  actually  wetted ;  and  therefore 
it  is  not  surprising  to  find  that  basaltic  and  other  rocks 
containing  much  iron  decay  more  rapidly  on  the  side 
which  faces  the  rainiest  quarter.  Not  that  the  force 
of  the  rain  makes  so  much  impression  on  them  as  on 
softer  rocks,  but  that  the  wet  enables  the  oxygen  to 
work  faster.  The  decay  is  not  confined  to  the  surface, 
moreover,  for  all  rocks,  even  those  which  are  most 
close  and  compact  and  are  called  impervious,  absorb 
some  amount  of  moisture,  and  this  also  finds  entrance 
through  the  cracks  and  joints,  from  which  no  large 
mass  of  rock  is  ever  entirely  free.  These  joints  are  es- 
pecially well  developed  in  the  basalt — an  ancient  lava — 
which,  in  cooling  down  from  the  molten  stnfe,  has 
shrunk  and  contracted  into  columns  having  from  tnree 
to  nine  faces,  and  measuring  from  a  few  inches  to 
several  feet  across,  The  rain,  of  course,  easily  finds 


Pioneer  Labourers  $1 

its  way  in  between  these  columns  ;  but  patches  of  wet 
and  brown  stains  are  also  found  actually  inside  the 
columns  themselves,  when  these  are  broken  open, 
showing  that  moisture  has  been  sucked  up  by  the 
rock. 

Now,  water  in  the  natural  state  always  contains 
some  amount  of  air  dissolved  in  it,  and,  wherever  the 
water  penetrates,  there  the  oxygen  of  the  air  penetrates 
also,  and  lays  hold  of  any  iron  that  comes  in  its  way, 
as  we  see  by  the  stains  that  it  has  done  in  this  instance. 

The  iron  of  the  basalt  is  not,  indeed,  pure  iron,  being 
already  combined  with  some  amount  of  oxygen,  but  it 
does  not  acquire  the  reddish-brown  colour  of  what  we 
familiarly  call  '  rust '  until  it  has  absorbed  as  much 
oxygen  as  it  can  hold.  In  this  condition  it  is,  of 
course,  heavier,  and,  as  we  have  seen,  softer  than 
before,  and  is  therefore  more  easily  washed  or  blown 
away  from  the  surface.  But  it  is  also  more  bulky,  and 
takes  up  more  space  than  it  did  before,  so  that  if  it 
be  formed  inside  the  rock  where  it  has  not  room  to 
expand,  the  rock  is  cracked  by  it.  This,  of  course, 
opens  the  way  for  more  water  and  more  oxygen  to 
enter,  and  so  the  work  proceeds,  and  the  decay  goes 
deeper  and  deeper. 

We  have  chosen  iron-rust  as  a  sample  of  the  way  in 
which  oxygen  works  because  it  is  one  of  which  we  all 
know  something,  but  it  must  not  be  forgotten  that  this 
is  only  one  of  many  oxides  formed  in  the  rocks  ;  and  that 
whenever  oxygen  combines  with  any  other  substance 
in  a  rock  to  form  an  oxide,  it  makes  that  substance 
take  up  more  room  than  before,  and  so  the  rock  is 
cracked  and  crumbled.  The  other  gas,  carbon  dioxide, 
\vorks  in  a  different  way,  though  it  also  helps  the 


22  Pioneer  Labourers 

oxygen  to  rust  iron  faster  than  it  could  do  alone.  But 
when  it  works  on  its  own  account  it  is  by  combining 
with  such  substances  as  lime,  potash,  soda  and  mag- 
nesia, which  it  makes  much  more  soluble  than  they 
were  before. 

Some  rocks  are  said  to  be  impervious,  or  '  water- 
proof,' but  this  only  means  that  they  allow  water  to 
enter  so  very  slowly  that,  unless  they  are  actually 
soaking  in  it  for  some  time,  hardly  any  is  taken  up. 
And  so,  in  a  similar  way,  some  minerals  are  called  in- 
soluble, which  again  means  only  that  pure  water  has 
very  little  effect  upon  them,  dissolves  them  so  very 
slowly  that  it  hardly  seems  to  do  so  at  all.  For  some 
effect  it  has  upon  every  known  mineral,  unless  it  be 
perhaps  upon  gold  and  platinum.  But  water  in  nature 
is  never  perfectly  pure;  how  can  it  be,  since  it  dis- 
solves some,  though  it  may  be  only  a  very  minute 
quantity,  of  everything  through,  or  over,  which  it 
passes  ?  Its  dissolving  powers  are  greatly  increased, 
too,  by  the  addition  of  carbon  dioxide — the  gas  we  are 
now  speaking  of — which  is  being  constantly  produced 
both  in  earth  and  air,  by  the  decay  of  vegetable  matter 
in  the  one,  and  by  the  lungs  ot  animals,  fires  and 
furnaces,  in  the  other. 

The  rain,  as  it  descends  from  the  clouds,  washes 
down  with  it  some  of  this  gas,  and  if  it  comes  in  con- 
tact with  such  a  rock  as  limestone,  soon  makes  an  im- 
pression upon  it  Chalk,  limestone  and  marble,  are  all 
composed  of  carbonate  of  lime,  softer  or  harder,  the 
lime  being  already  united  with  a  certain  quantity  of 
carbon  dioxide.  But  in  this  condition  it  dissolves  so 
very  slowly  as  to  be  called  insoluble  in  pure  water. 
When  it  comes  in  contact  with  the  gas,  however, 


Pioneer  Labourers  23 

whether  in  air  or  water,  it  takes  up  double  the  quantity 
it  had  before,  and  is  converted  into  a  double,  or 
bi-carbonate,  which  is  easily  dissolved  and  washed 
away.  Marble  slabs  which  are  exposed  to  the  weather 
in  such  a  climate  as  that  of  Edinburgh  are  com- 
pletely destroyed  in  this  way  in  less  than  a  hundred 
years. 

Even  rocks  which  consist  only  in  part  of  carbonate 
of  lime  are  open  to  the  attacks  of  carbon  dioxide.  For 
instance,  there  are  the  sandstones.  The  grains  are 
hard  enough,  being  composed  of  silica,  and  if  they  are 
cemented  together  with  silica,  too,  the  stone  is  one  of 
the  most  durable  that  can  be  found,  neither  water  nor 
gases,  together  or  separately,  being  able  to  make  much 
impression  upon  it.  But  if  the  grains  are  cemented 
together  by  iron  oxide,  or  by  carbonate  of  lime,  it  is 
quite  another  matter.  Oxygen  or  carbon  dioxide  may 
get  to  work  on  the  cement,  and  as  that  is  removed  the 
grains  fall  apart  and  become  sand. 

Then,  again,  there  are  the  granites,  composed  of  three 
minerals,  quartz,  mica,  and  felspar ;  the  first  is  silica, 
like  flint,  and  equally  hard,  and  if  the  rock  consist 
mainly  of  quartz,  as  some  granites  do,  it  is  of  course 
extremely  durable,  for,  besides  resisting  the  action  of 
the  gases,  it  also  admits  very  little  water.  If,  on  the 
other  hand,  the  felspar  predominates,  the  rock  is  softer, 
and  water  finds  an  easier  entrance ;  but,  besides  this, 
the  felspar — which  is  clay  without  the  water,  and  in  a 
crystallized  form— contains  either  potash  or  soda,  and 
often  lime  as  well,  and  any  one  of  these  is  easily 
attacked  and  made  soluble  by  union  with  carbon 
dioxide.  Once  converted  into  carbonates,  or  bicar- 
bonates,  as  the  case  may  be,  these  are  easily  dissolved 


24  Pioneer  Labourers 

and  washed  away  by  the  next  shower.  As  for  the 
single  carbonate  of  potash,  it  does  not  need  even  a 
shower  to  help  it,  but  melts  away  in  the  moisture  of 
the  air,  as  anyone  may  know  who  has  ever  tried  to  keep 
it  wrapped  in  paper. 

The  carbonates  being  thus  removed,  and  the  clayey 
part  of  the  felspar  softened  and  washed  away  to  form 
beds  of  clay  elsewhere,  the  crystals  of  quartz  and  mica 
must  needs  fall  apart,  and  so  the  work  of  breaking 
down  the  rock  goes  on. 

But  nature's  labourers  proceed  upon  the  principle 
that  '  union  is  strength,'  and  they  so  constantly  work  in 
company  that  it  is  a  difficult  matter  to  apportion  the 
result  of  their  labours  exactly  each  to  each.  We  have 
already  seen  how  water  dissolves ;  we  must  now  look 
at  it  in  another  capacity,  and  see  how  it  acts  the  part 
of  crowbar  and  pickaxe,  and  even  at  times  of  dynamite. 
A  cubic  inch  of  water,  when  converted  into  steam, 
occupies  just  1,728  times  as  much  space  as  it  did 
before,  and  it  expands  with  such  violent  force  as  to 
shatter  the  rocks  beneath  which  it  is  confined.  Such 
explosions  as  this  sometimes  occur  during  volcanic 
eruptions,  water  having  found  its  way  down  through  the 
earth  till  it  has  come  into  contact  with  some  mass  of 
molten  lava,  which  has  converted  it  into  steam,  and 
made  it  a  powerful  engine  of  destruction. 

But  water  expands  also,  though  in  a  less  degree, 
when  it  is  converted  into  ice,  and  it  is  under  this  aspect 
that  we  are  most  familiar  with  its  doings.  Ice  occupies 
only  one-fifteenth  more  space  than  the  water  from 
which  it  is  formed,  and,  compared  with  the  expansion 
which  takes  place  in  the  formation  of  steam,  this 
increase  may  sound  insignificant.  But  its  effects  are 


Pioneer  Labourers  25 

very  far  indeed  from  being  insignificant  the  force  which 
it  exerts  being  simply  irresistible. 

Water,  as  we  have  said,  finds  entrance  everywhere, 
more  or  less,  in  one  way  or  another,  and  wherever  it 
is  sufficiently  near  the  surface  to  freeze,  there  it  has  the 
effect  of  a  multitude  of  crowbars  and  chisels  of  all  sorts 
and  sizes  wielded  by  an  invisible  army  of  workmen.  It 
widens  every  crack  in  which  it  is  formed,  prizing  up 
large  masses  of  rock  many  tons  in  weight,  loosening 
and  eventually  forcing  them  off,  and  also  doing  finer 
work,  such  as  chiselling  off  splinters  and  particles  of  all 
sizes,  large  and  small.  The  immense  piles  of  rubbish 
which  strew  the  surface  of  the  glaciers,  and  consist  of 
sand,  grit,  and  fragments  of  all  dimensions,  are  due 
mainly  to  the  action  of  the  frost,  which  in  mountain 
regions  recurs  not  merely  every  winter,  but  every  night 
throughout  the  year. 

Even  in  England,  where  frosts  are  less  frequent,  as 
well  as  less  severe,  and  therefore  penetrate  to  a  less 
depth,  the  tops  of  the  higher  hills  are  often  buried 
some  feet  deep  with  wreckage  of  the  frost's  making ; 
only  very  often  we  fail  to  realize  what  is  going  on 
because  the  loosened  fragments  are  being  constantly 
washed  away  by  the  rain.  In  more  severe  climates  the 
waste  is  immense,  the  hill-tops  and  mountains  being 
crowded  with  great  blocks  and  slabs  wedged  off  by  the 
frost ;  and  this  is  the  first  step  towards  their  being 
crumbled  into  soil.  The  more  water  a  rock  absorbs, 
the  more  easily,  of  course,  it  is  cracked  and  splintered 
by  the  frost ;  and  though  we  may  not,  many  of  us,  have 
much  opportunity  of  observing  the  work  done  in  this 
way  upon  the  rocks,  we  all  know  something  of  glasses 
and  pipes  cracked  by  the  freezing  of  the  water  in  them* 


26  Pioneer  Labourers 

We  may  have  seen,  too,  how  fence-posts  are  sometimes 
lifted  out  of  their  places,  simply  by  the  heaving  of  the 
soil  beneath  them ;  the  water  in  the  pores  of  the  soil 
having  frozen  and  swelled,  and  forced  them  up. 

But  even  where  there  is  no  rain,  and  no  ice  can 
therefore  be  formed  in  their  cracks  and  crevices,  the 
rocks  themselves  feel  changes  of  temperature ;  and 
where  these  changes  are  sudden,  severe,  and  often 
repeated,  no  rock  is  strong  enough  to  stand  against 
them.  The  rocks  of  the  Sahara  and  other  similar 
regions  are  crumbled  into  sand  simply  by  the  intense 
heat  of  the  day  and  the  sharp  frost  at  night.  The  one 
causes  them  to  expand  and  the  other  makes  them 
contract ;  and  between  the  two  the  outer  grains  are  being 
constantly  loosened  and  forced  out  of  their  places 

When  the  'Glass  Road'  was  being  made  in  the 
famous  Yellowstone  Park  (Wyoming,  U.S.A.),  some 
huge  blocks  of  obsidian,  or  volcanic  glass,  were  found 
to  come  in  the  way ;  and  as  they  were  too  hard  to  be 
either  hewn  or  drilled,  and  could  therefore  not  be 
blasted,  the  engineer  in  charge  had  large  fires  lighted 
on  the  top.  When  the  rocks  were  scorching  hot,  a 
sudden  deluge  of  cold  water  was  poured  upon  them 
from  the  neighbouring  lake,  and  by  these  means  they 
were  thoroughly  shattered.  This  is  of  course  a  very 
extreme  instance  of  the  effect  produced  by  changes  of 
temperature,  and  such  as  would  seldom,  if  ever,  occur 
in  nature;  but  it  may  serve  to  show  how  very  real 
these  effects  are. 

Of  the  other  ways  in  which  the  rocks  are  broken  up, 
it  will  not  be  needful  to  say  much.  We  must  pass 
over  with  brief  mention  the  work  done  by  sand,  set  in 
motion  by  wind  or  water.,  which  cuts  and  polishes  the 


Pioneer  Labourer  $  27 

very  hardest  rocks  when  driven  against  them  by  the 
former,  and,  when  driven  by  water,  has  produced  the 
great  caftons,  or  narrow  gorges  some  thousands  of  feet 
in  depth,  with  which  we  are  familiar  in  California. 
Nor  will  it  be  necessary  to  dwell  upon  the  hammering, 
battering  effects  of  the  rains,  which  are  sufficiently 
obvious  even  in  our  climate,  and  are  of  course  greatly 
intensified  in  tropical  regions. 

But  a  few  words  must  be  said  about  the  glaciers, 
those  frozen  rivers,  which  are  among  the  mightiest  of 
nature's  grinders.  Looking  down  upon  a  glacier,  and 
seeing  it  strewn  with  the  blocks  of  stone  and  vast 
heaps  of  rubbish  which  have  fallen  upon  it  from  the 
cliffs  above,  dislodged  by  the  frost,  we  should  be  dis- 
posed to  think  it  a  very  rough  labourer  indeed,  merely 
engaged  in  carting  away  the  wreckage  made  by  others. 
But  this  would  be  a  great  mistake.  A  little  brawling 
stream  makes,  it  is  true,  far  more  noise  and  fuss,  and 
even  more  show  of  work,  as  it  rolls  the  pebbles  over  in 
the  bed  which  it  is  perpetually  deepening  and  widen- 
ing; but  the  glacier  is  a  giant  mill-stone,  pressing 
upon  the  rocks  beneath  with  a  power  which  is  simply 
irresistible. 

Glaciers  move  on  in  solemn  silence,  it  may  be  at  the 
rate  of  perhaps  only  an  inch  or  two  in  the  twenty-four 
hours,  but  they  go  on  steadily  and  noiselessly,  and  as 
they  go,  they  grind  the  rocks  beneath  to  a  powder  so 
fine,  that  when  at  last  it  escapes  from  the  glacier-mill 
in  the  stream,  which  flows  out  from  beneath,  it  has 
been  reduced  to  nothing  but  mud. 

One  other  grinder,  equally  mighty  and  thorough, 
but  by  no  means  silent,  must  be  mentioned  in  con- 
clusion. This  is  the  volcano,  which,  besides  pouring 


28  Pioneer  Labourers 

forth  streams  of  lava,  often  buries  the  surrounding 
country  many  feet  deep  in  the  finest  dust  and  ashes, 
or  in  mud,  if  the  eruption  be  accompanied,  as  it  often 
is,  by  rain. 

Such,  then,  are  the  principal  pioneer -labourers 
employed  in  breaking  down  the  rocks.  By  the  com- 
bined efforts  of  the  gases  and  moisture  of  the  atmo- 
sphere, by  heat  and  frost,  wind  and  rain,  by  rivers  and 
streams,  by  glacier  and  volcano,  the  rocks  are  gradually 
split  up,  worn  away,  and  reduced  on  the  surface  to  a 
condition  of  softness. 

In  tropical  regions,  where  the  air  is  always  moist, 
and  the  rainfall  large  and  violent,  some  rocks  are 
decayed  and  softened  to  a  depth  of  a  hundred  or  two 
hundred  feet.  In  drier  climates,  the  work  proceeds 
more  slowly  and  to  a  less  depth,  the  rock  beneath 
being  to  some  extent  protected  from  the  weather  by 
the  looser  material  above,  when  this  is  left  to  accu- 
mulate. 

But  the  labourers  which  we  have  been  thus  briefly 
considering  are  only  pioneers.  They  accomplish  only 
the  rougher  work  of  preparation,  and  very  much 
remains  to  be  done  before  anything  that  can  properly 
be  called  '  soil '  is  ready  for  the  crops. 


III. 

SOIL-MAKERS 

STANDING  before  some  bare  expanse  of  hard  rock,  we 
might  well  wonder,  if  we  knew  nothing  of  the  subject, 
how  it  should  ever  be  converted  into  a  surface  fit  for 
the  support  of  vegetation.  There  may  be  vineyards 
close  by  showing  that  it  has  been  done  in  other 
instances  ;  but  what  is  to  be  the  first  step  ? 

Ploughs,  even  steam  ploughs,  are  quite  useless  here, 
and  man  must  wait  until  the  work  is  done  for  him,  as  it 
will  be,  and  very  thoroughly,  too,  in  the  end ;  but  it 
will  be  done  deliberately,  without  hurry  or  bustle, 
and  it  may  take  years  or  centuries.  Meanwhile,  it  is  of 
no  use  for  him  to  look  with  longing  eyes  upon  the 
rock ;  he  can't  plough  it,  and  he  would  be  mad  to  sow 
it,  for  any  seed  he  could  sow  would  be  washed  or  blown 
away. 

And  yet  if  he  were  to  look  closely  at  the  seemingly 
bare  surface,  he  might,  and  in  most  cases  would,  find 
that  it  was  not  altogether  bare  and  barren.  He  might 
need  a  microscope  to  show  him  the  truth,  but  if  he 
understood  what  he  saw,  he  would  discover  that  the 
rock  had  been  sown. 

The  pioneer  labourers,  far  from  finishing,  have 
hardly  begun  their  work  here,  but  seed  fcas  been 


30  Soil- Makers 

scattered  in  this  unlikely  place ;  and  if  we  look  at  what 
has  been  done  in  other  similar  places,  we  shall  see  that 
it  has  not  been  wasted. 

Floating  about  in  the  air,  invisible,  but  in  countless 
multitudes,  are — what  answer  to  the  seeds  of  other 
plants — the  spores  of  those  strange  forms  of  vegetation 
called  lichens,  which,  except  in  towns,  are  to  be  seen 
beautifying  every  old  wall,  roof,  and  tombstone.  They 
are  so  light  that  they  cannot  settle  at  all,  except  when 
the  air  is  still,  and  even  then  the  least  breath  would 
disturb  them. 

But  they  are  sticky,  and  this  stickiness  enables 
them  to  cling  fast  even  to  the  bare  rock.  Once 
settled,  they  begin  to  grow,  and  are  the  first  traces 
of  vegetable  life  to  make  their  appearance  upon  recent 
streams  of  lava.  They  may  truly  be  called  'traces/ 
for  the  first-comers  are  nothing  more  than  helpless- 
looking  stains,  or  dust,  hardly  noticeable  except  by 
those  on  the  look-out  for  them ;  and  one  would  have 
said  anything  but  dangerous  to  the  rock,  for  they  look 
not  only  perfectly  inactive,  but  entirely  lifeless. 

Just  so  a  stranger  to  the  tropics,  newly-arrived, 
would  see  with  perfect  unconcern  a  single  small  ant 
making  its  way  across  the  floor  of  his  room,  a  helpless 
insignificant  insect,  which  he  could  crush  with  a 
finger.  But  the  native  knows  better.  He  could  crush 
the  one,  but  behind  it  is  a  mighty  column  of  ants  two  or 
three  hundred  yards  long  coming  to  take  possession  of 
the  house,  and  there  is  nothing  to  be  done,  as  he  knows, 
but  to  give  it  up  to  them  and  retreat  for  the  time.  The 
ants  come  and  go  again  when  their  work  is  done ;  but 
the  lichens  come  to  stay  until  displaced  by  other  and 
more  important  members  of  the  family,  for  they  are  the 


Soil-Makers  31 

advance  guard  of  the  vegetable  host,  and  their  appear- 
ance signifies  that  the  fate  of  the  lava  surface  upon 
which  they  have  settled  is  sealed.  Nature  has  marked 
it  for  her  own.  She  is  going  to  break  down  the  hard, 
barren  surface  sooner  or  latter,  and  convert  it  into  a 
fertile,  productive  soil,  fit  for  field  or  vineyard. 

The  lava  has  resisted  for  some  time.  For  years  it 
did  not  even  cool,  and  it  has  scorched  innumerable  lichen 
spores  to  death  in  their  attempt  to  settle  upon  it.  Even 
when  the  surface  had  cooled  there  was  for  a  long  time 
heat  enough  within  to  dry  all  the  life  out  of  them  ;  while 
multitudes  have  found  the  glossy  surface  too  glossy 
even  for  their  powers  of  clinging,  and  have  been  blown 
away  as  fast  as  they  came.  There  are  some  streams  of 
lava  which  are  as  glossy  now  as  when  they  were  first 
poured  forth  three  or  four  hundred  years  ago,  and  no 
lichens  have  as  yet  managed  to  gain  a  footing  there. 
But  they  are  not  generally  kept  so  long  at  bay.  They 
return  to  the  charge  again  and  again,  helped  by  the 
pioneers  who  have  also  been  at  work  meantime,  and 
have  gradually  roughened  the  surface  a  little,  or  at 
least  have  taken  off  some  of  the  glossiness ;  and  at 
last  the  spores  manage  to  settle  and  fix  themselves 
so  firmly  that  neither  wind  nor  rain  can  dislodge 
them,  and  they  begin  to  grow  and  spread  at  their 
ease. 

Then,  in  spite  of  what  was  said  in  the  previous 
chapter,  these  vegetables,  at  all  events,  must  live  on  air 
and  water  ? 

Not  at  all !  Lichens  are  very  substantial  feeders 
indeed,  and  consume  more  mineral  matter  in  propor- 
tion to  their  size  than  any  other  plants. 

But  if  it  is  locked  up,  and  not  available  until  the  rock 


32  Soil- Makers 

is  crumbled  down  and  softened  enough  for  the  roots  to 
penetrate  into  it,  how  can  they  get  at  it  ? 

In  one  respect  lichens  are  like  seaweeds,  for  they 
have  no  roots  through  which  to  take  up  food.  But 
they  are  unlike  them  in  another,  for  they  do  feed  upon 
the  rocks ;  and  even  these  first-comers,  the  humblest 
members  of  the  family,  mere  stains  in  appearance, 
contrive  to  make  a  living  wherever  they  can  gain  a 
footing.  Not,  of  course,  that  they  take  up  particles  of 
stone,  but,  being  all  of  them  strongly  acid,  they  are 
able  to  dissolve  it  first  and  then  absorb  what  they 
need ;  and  though  they  are  at  first  so  minute  as  to  be 
almost  microscopic,  no  rock  can  resist  them. 

The  '  stains  '  spread  and  grow  and  decay,  and  by 
degrees  there  is  formed  from  their  remains  a  thin  film 
of  soil,  in  which  lichens  of  a  much  larger  growth  are 
able  to  flourish.  They  are  all  more  or  less  harsh  to 
the  touch ;  and  the  ashy,  steely  grays,  and  rusty  browns, 
and  the  brilliant  yellow  and  orange  of  their  colouring 
remind  one  more  of  minerals  than  of  vegetables,  which 
is  not  surprising,  considering  that  often  a  fifth  part  of 
their  substance,  and  sometimes  much  more,  consists 
of  solid  matter  eaten  from  the  rocks. 

When  the  lichens  have  had  possession  for  a  time, 
and  have  prepared  the  way,  they  are  followed  by  mosses, 
which  absorb  much  moisture  from  the  air  and  help  to 
decay  the  rock  by  keeping  the  surface  damp,  for,  as  we 
have  already  seen,  where  water  is  there  frost  and  gases 
can  get  to  work.  The  mosses  grow  and  die  in  their 
turn,  and  their  remains,  with  those  of  lichens  and 
loosened  particles  of  rock,  as  well  as  the  dead  bodies 
of  such  minute  insects  as  may  have  found  a  dwelling 
among  them,  together  form  something  deserving  the 


Soil-Makers  33 

name  of  mould,  which  will  support  plants  of  quite 
large  size.  These  are  followed  by  dwarf  shrubs,  whose 
roots  help  on  the  work  more  rapidly ;  and  in  a  century, 
more  or  less,  the  stream  of  lava  is  usually  converted 
into  soil  fit  for  the  planting  of  vineyards  and  gardens. 

Lichens  attack  not  only  lava,  however,  but  also 
granites,  slates,  and  even  hard  crystalline  quartz-rock, 
wherever  there  is  sufficient  moisture.  No  rock  is 
proof  against  them  ;  almost  any  climate  suits  them, 
hot  or  cold,  moist  or  dry,  and  they  are  the  last  signs  of 
vegetation  to  be  lost  sight  of  by  the  mountaineer  as  he 
ascends  towards  the  region  of  perpetual  snow  and  bare 
peaks,  whither  even  they  are  unable  to  follow.  But 
they,  flourish  best  and  do  most  work  where  there  is 
moisture. 

They  quickly  make  their  appearance  upon  any 
freshly  exposed  surface  of  granite,  though  we  may 
often  need  a  microscope  for  their  detection.  In  one 
instance,  at  least,  however,  their  brilliant  colouring  and, 
what  is  more  unusual,  their  sweet  scent  betray  them. 

The  so-called  Violet-stone  found  on  the  summit  of 
the  Brocken  is  nothing  but  bare  granite,  covered  with 
a  film  of  what  looks  like  scarlet  dust,  which  smells  like 
violets,  especially  on  being  rubbed.  It  looks  so  per- 
fectly harmless,  that  one  can  hardly  believe  it  possible 
it  should  affect  the  solid  granite  in  any  way.  Yet  it 
does;  to  a  very  small  extent,  indeed,  but  just  sufficiently 
to  prepare  the  way  for  two  large  brown  lichens,  which 
are  the  next  to  make  their  appearance ;  and  then  the 
work  proceeds  more  rapidly  in  the  way  already 
described,  until  at  last  tall  pine-trees  rear  their  heads, 
and  find  sufficient  food  and  foothold,  where  but  a  few 
years  before  there  was  nothing  but  a  bare  surface. 

3 


34  Soil-Makers 

The  pines  are  much  more  imposing  in  appearance, 
and  look  capable  of  much  greater  exertion  (as  they  are 
in  some  ways),  but  they  could  not  have  done  what  the 
lichen  does ;  and,  but  for  the  lichen,  they  could  never 
have  grown  here  at  all. 

We  see,  then,  that  nature  makes  large  use  of  the 
humbler  vegetables  in  preparing  the  way  for  the  crops 
which  are  eventually  to  be  grown  ;  but  it  must  not  be 
forgotten  that  the  process  of  preparation  is  an  exceed- 
ingly complicated  one,  performed,  not  by  one  set  of 
labourers,  but  by  many,  all  working  together. 

Even  a  very  scanty  covering  of  vegetation  does 
something,  it  is  true,  to  protect  the  rock  below  against 
the  battering  of  the  rain  and  against  changes  of 
temperature ;  but,  on  the  other  hand,  it  keeps  the  rock 
damp,  and  moisture  not  only  dissolves  on  its  own 
account,  but  attracts  gases  from  the  atmosphere,  which 
greatly  increase  its  powers  in  this  respect.  Then,  too, 
the  powerful  gas,  carbon  dioxide,  is  also  formed  in  the 
soil  itself  by  the  decay  of  vegetable  matter,  besides 
being  given  off  by  living  roots,  and  this  greatly  enhances 
the  dissolving  power  of  water. 

.  Lichens,  as  we  have  said,  are  able  to  eat  into  the 
rock,  as  oxygen  eats  into  iron,  and  by  similar  means, 
for  both  are  strongly  acid ;  and  on  removing  lichens 
from  a  stone  one  sees  indentations,  similar  to  those 
left  on  a  piece  of  iron  by  the  removal  of  rust.  But 
what  is  true  of  lichens  is  true  in  a  degree  of  all 
plants.  The  roots  of  all  plants,  that  is  to  say,  are 
acid,  though  in  a  less  degree,  especially  the  young, 
fine,  hair-like  roots ;  and  if  these  find  their  way 
through  the  thin  soil  to  the  rock  beneath,  they  eat 
into  it,  leaving  a  distinct  impression  of  themselves 


Soil-  Makers  3  5 

upon  it  when  they  are  removed.  The  finest  hair  will 
leave  its  mark. 

The  amount  of  acid  contained  in  a  delicate  little 
rootlet,  or  even  in  a  lichen,  is,  of  course,  very  small — 
quite  insufficient,  one  would  say,  for  the  work  it  has  to 
do ;  and  so  it  is  in  our  hands.  That  is  to  say,  if  we 
get  from  the  chemist  and  apply  the  self-same  acid  in 
similar  quantities,  we  cannot  do  with  it  what  the 
lichen  and  other  plants  do ;  we  cannot  make  as  much 
impression  upon  the  rock.  For  the  lichen,  though  it 
may  look  dead,  is  alive,  and  the  roots  are  alive;  and 
living  things,  however  humble,  produce  wonderful 
effects,  such  as  dead  matter  never  can. 

But  roots  also  exert  a  powerful  influence  upon  the 
rocks  in  another  way.  A  very  common  method  of 
breaking  up  the  rocks  in  use  with  quarrymen  is  to 
drive  into  them  plugs  of  very  dry  wood.  These  plugs 
are  then  watered,  whereupon  they  swell  with  such  force 
as  to  split  even  the  hardest  granite.  Roots  act  in  a 
similar  manner,  though  less  violently  ;  and  by  swelling 
in  every  direction,  they  gradually  widen  any  cracks 
into  which  they  have  found  their  way,  and  actually 
wedge  off  large  slices  from  the  sides  of  hills  and  cliffs. 

In  the  neighbourhood  of  Mount  Etna  people  make 
the  roots  of  the  prickly  pear  work  for  them  in  this  way, 
for  they  want  to  hasten  the  breaking  up  of  the  lava,  in 
order  that  they  may  turn  it  to  account  as  soon  as 
possible.  The  lava  cracks  as  it  cools,  and  in  every 
crevice  that  appears  they  insert  a  branch  of  this  cactus, 
which  not  only  lives,  but  soon  begins  to  grow,  thanks 
to  the  warmth,  sunshine,  and  moisture  of  the  genial 
climate.  Its  roots  cannot,  of  course,  penetrate  the 
lava,  but  they  can  and  do  make  their  way  into  every 


36  Soil-Makers 

crack  and  cranny  within  reach,  and  as  they  grow  and 
swell  they  break  up  the  rock  into  fragments. 

As  to  what  the  plant  lives  upon  in  the  absence  of 
soil,  it  must  be  remembered  that  often  a  very  little 
mineral  food  is  enough  for  a  plant,  if  only  it  is  able  to 
make  the  most  of  what  there  is  and  has  plenty  of 
water ;  then  we  must  remember,  too,  that  lava  is 
especially  rich  in  the  materials  required  by  plants,  and 
that  water  flowing  over  it,  or  draining  through  it, 
would  certainly  dissolve  some  of  these  materials  and 
bring  them  within  reach  of  the  roots,  which  would 
obtain  them  in  this  way  quite  as  well  as  from  soil ; 
and  then,  finally,  the  whole  cactus  family,  like  the 
lichens,  are  furnished  with  large  quantities  of  acid, 
by  which  they  take  up  an  altogether  unusual  amount 
of  mineral  matter,  and  they  are  apparently  able  to 
take  it  up,  as  the  lichens  do,  from  the  solid  sub- 
stances, at  least,  to  some  extent,  for  in  their  native 
land,  America,  they  are  to  be  seen  growing  out  of 
the  rocks. 

Though  we  may  not  have  had  the  opportunity  of 
noticing  how  roots  split  the  rocks,  we  are  all  probably 
familiar  with  the  power  which  they  exert  on  a  smaller 
scale  and  upon  humbler  material.  Who  that  has 
'  gardened,'  even  to  the  extent  of  growing  a  few  ferns, 
but  has  some  time  or  other  known  a  pot  cracked  by 
the  efforts  of  the  roots  to  find  room  when  they  have 
outgrown  their  domicile  ? 

But  we  have  now  to  consider  other  means  by  which 
nature  prepares  the  soil.  Hitherto  we  have  confined 
our  attention  to  what  is  done  with  the  rocks  on  the 
spot,  the  soil  being  left  where  it  is  made ;  but  this  pro- 
ceeding is  attended  by  certain  disadvantages :  the  soil 


Soil- Makers  37 

rarely  attains  any  great  depth,  for  one  thing,  as  the 
rock  below  is  protected  more  or  less  from  frost ;  and 
then,  again,  generally  speaking,  one  kind  of  rock  alone 
does  not  contain  all  that  is  necessary  to  make  a  really 
fertile  soil  rich  in  all  the  various  mineral  matter  re- 
quired for  luxuriant  crops.  If  we  look  at  those  soils 
which  are  acknowledged  to  be  the  richest  in  the  world 
we  shall  find  that,  as  a  rule,  they  have  been  much 
mixed.  We  say,  as  a  rule,  because  most  of  the  lavas 
are  rich  enough  in  the  minerals  which  plants  require, 
and  are  also  so  well  drained,  thanks  to  the  cracks  and 
fissures  within,  that  they  do  form  most  productive  soil 
when  simply  crumbled  down. 

With  the  granites,  however,  the  case  is  very 
different :  they  are  poor  in  the  necessary  minerals  to 
begin  with,  and  what  they  do  possess  is,  as  we  have 
seen,  dissolved,  and  in  great  part  washed  away. 
Granite  slopes  are  poor  and  sandy,  therefore,  while 
the  clay  deposited  at  their  feet  is  too  stiff  and  compact 
to  be  fertile ;  and  nature  seems  to  tell  the  farmer  as 
plainly  as  she  can  that  in  most  cases  he  will  not  find  it 
worth  his  while  to  try  and  grow  wheat  either  on  the 
hills  or  in  the  dales  of  a  granite  district.  Of  course, 
where  granite  decays  on  the  level,  and  its  various 
minerals  remain,  all  crumbled  down  and  mixed  to- 
gether, it  is  naturally  more  fertile  than  where  the  best 
of  them  are  washed  away;  and  thus  we  find  that 
the  granite  soils  of  the  Scilly  Isles  are  far  more  pro- 
ductive than  those  of  the  Scotch  hills,  and  are  capable 
of  bearing  good  crops  of  corn,  in  part,  at  least,  because 
less  of  the  potash,  has  been  washed  away  from  them. 
But  some  thanks  are  also  due  to  the  more  genial 
climate,  for  on  the  granite  highlands  of  Dartmoor 


38  Soil-Makers 

there  is  no  vegetation  but  heath  and  coarse  grass,  and 
though  one  has  heard  of  labourers  attempting  to  culti- 
vate portions,  and  not  without  some  success,  it  is  im- 
possible to  say  that  the  soil  is  naturally  adapted  for 
either  field  or  garden  crops.  The  moor  is  flat  enough, 
indeed,  to  prevent  the  separation  of  the  sand  and  clay, 
and  such  minerals  as  the  granite  possesses  are  fairly 
enough  mixed  without  much  loss  by  washing ;  but  the 
natural  poverty  of  the  rock  is  aggravated  by  its  elevated 
situation  on  the  one  hand,  and  by  the  shallowness  ol 
the  soil  on  the  other,  and  the  soil  therefore  labours 
under  the  two  great  disadvantages  of  a  cold  climate 
and  want  of  drainage.  To  the  latter  of  these  are  due 
the  many  bogs  which  abound,  not  only  on  Dartmoor, 
but  on  the  granites  of  Scotland,  and  the  serpentine 
rocks  of  the  Lizard  as  well — everywhere,  in  fact,  where 
the  soil  lacks  depth  and  the  underlying  rock  is  so  close 
and  compact  that  water  collects  on  the  surface  instead 
of  draining  through. 

These  moorlands  and  bog-lands  are  accordingly 
dubbed  '  waste '  by  those  who  look  at  them  only  with 
the  eye  of  the  farmer,  and  are  reckoned  among  the 
twenty  odd  million  of  uncultivated  acres  in  Great 
Britain,  thirteen  million  of  which  are  pronounced  alto- 
gether irreclaimable. 

Waste  lands !  because  the  farmer  cannot  profitably 
bring  them  under  his  plough  and  harrow !  as  if  that 
were  the  only  end  for  which  soil  could  possibly  be 
wanted,  and  as  if  man  and  his  domestic  animals  were 
the  only  creatures  requiring  to  be  fed.  Waste  lands  ! 
where  grouse  and  black  game  feed  upon  the  heath 
buds,  where  bog  and  moor  are  the  summer  haunt  of 
curlew  and  plover,  not  to  mention  the  countless  other 


Soil-Maker*  39 

feathered  fowls,  not  classed  as  '  game/  which  yet  form 
part  of  the  live  stock  for  which  nature  grows  the  varied 
crops  of  the  '  great  farm.' 

The  soil  of  the  chalk-downs  is  like  that  of  the  granite 
table-lands  in  one  respect,  that  it  is  derived  chiefly 
from  the  rock  beneath,  and  has  had  little  advantage  of 
intermixture  with  others ;  but — and  this  makes  a  vast 
difference — the  underlying  chalk  absorbs  water  readily, 
like  a  sponge,  so  that  bogs  have  no  chance  of  forming. 
The  downs  grow  excellent  pasture,  and  are  especially 
adapted  for  sheep-farming;  but  if  people  will  plough 
up  the  soft  fine  herbage  of  nature's  providing  and  try 
to  grow  corn  and  turnips  instead,  they  must  not  be 
surprised  if  they  get  poor  crops  in  return  for  much 
labour.  The  soil  wants  mixing  before  they  can  be 
grown  to  much  purpose  ;  and  since  the  other  minerals 
necessary  are  not  upon  the  spot,  the  farmer  must  fetch 
them  from  a  distance  before  he  can  grow  a  satisfactory 
crop — and  this  is  expensive. 

But  nature  has  labourers  at  her  command  who  can 
do  what  the  farmer  can  never  accomplish,  no  matter 
what  his  wealth  and  appliances.  Nature's  soil  has  been 
transported  wholesale,  not  once  only,  but  over  and  over 
again,  and  has  become  so  much  mixed  in  the  process 
that  no  soil  is  absolutely  pure,  even  though  it  be  pro- 
duced by  the  crumbling  down  of  one  kind  of  rock  only. 
For  every  rock  that  meets  our  eyes  was  formed  from 
others  more  ancient  still. 

Most  of  the  richest  soils  of  the  world  have  been 
mixed,  either  by  the  work  of  rivers,  or  by  that  of  other 
labourers  to  be  considered  by-and-by.  And  besides 
being  mixed,  they  have  in  many  cases  been  transported 
from  situations  where  they  were  comparatively  useless, 


40  Soft-Makers 

to  others  where  their  good  qualities  can  be  turned  to 
the  best  account. 

The  richest  soil  in  the  world  is  of  little  use  on  a  lofty 
mountain-top,  for  none  but  lowly  plants  can  stand  the 
cold  and  exposure,  and  anything  to  be  called  luxuriant 
vegetation  is  impossible.  Take  even  the  case  of  the 
Cheviot  Hills.  They  cannot  be  called  lofty,  but  their 
more  elevated  parts  are  too  exposed,  too  bleak,  for 
successful  cultivation,  in  spite  of  the  rich  soil,  which 
would  be  invaluable  for  farming  purposes  if  it  could  be: 
transported  to  a  more  genial  climate.  To  yield  its  full 
value,  this  soil  must  be  brought  down  to  a  lower  level, 
and  for  that  we  must  wait  nature's  time. 

But  in  numberless  other  instances  this  is  what  has 
been  done.  Soil  has  been  brought  down  from  the 
mountains,  where  it  must  have  been  comparatively 
unproductive ;  it  has  been  mixed  and  prepared,  and 
finally  spread  out  in  extensive  fields  ready  made  to  the 
farmer's  hand,  in  situations  where  his  crops  can  have 
the  warmth  and  moisture  which  are  essential  to  them. 

It  certainly  does  appear  perverse,  therefore,  that 
men  should  persist  in  trying  to  grow  crops  where  they 
seem  plainly  meant  to  feed  their  sheep  ;  and  that  they 
should  want  to  plough  up  moors  and  deer-forests  which 
could  never  make  productive  fields,  when  by  long  and 
most  elaborate  preparation  thousands  and  millions  of 
acres  have  been  provided  which  would  yield  abundant 
harvests  with  less  than  half  the  labour. 


IV. 

SOIL-CARRIERS 

WE  have  now  seen  by  what  means  the  rocks  are 
crumbled  down ;  but  in  many  cases  much  besides 
crumbling  is  necessary  to  convert  rock  into  good  soil. 
On  a  bleak  hill-top  the  crumbled  materials  will  be  of 
little  use  owing  to  the  climate,  though  they  may  be 
most  valuable  when  brought  down  to  the  lowlands. 
But,  more  than  this,  nearly  all  the  soils  which  we  look 
upon  as  especially  fertile  have  been  made  so  by  being 
mixed.  We  have  now  to  see  how  this  mixing  has  been 
effected,  and  how  the  crumbled  matter  of  the  rocks  has 
been  transferred  from  one  place  to  another. 

When  we  consider  which  are  the  best  corn-producing 
regions  of  the  earth,  our  thoughts  naturally  turn  first  to 
Egypt,  once  the  granary  of  the  world. 

And  what  is  Egypt  ?  '  The  gift  of  the  Nile,'  as  the 
ancient  historian  says.  The  soil  which  produces  such 
wonderful  crops  has  not  been  produced  by  the  decay 
of  the  rocks  upon  which  it  rests,  but  is  a  mixture  of 
soils  brought  in  great  part  from  the  lofty  mountains  of 
Abyssinia,  hundreds  of  miles  away.  The  only  fertile 
tracts  in  Abyssinia  itself  are  due  to  the  sediment 
washed  down  from  these  mountains,  which  are  rich  in 
the  minerals  most  desired  by  plants,  but,  like  the 


4  2  Soil-  Carriers 

Cheviot  Hills  already  mentioned,  unproductive,  owing 
to  their  height  and  the  consequently  severe  climate. 

The  top  of  this  magnificent  chain  of  mountains  is  a 
vast  table-land,  upon  which  the  rains  descend  heavily 
and  incessantly  during  some  three  or  four  months  of 
the  year,  the  fall  being  so  abundant  as  to  supply  five 
tremendous  mountain-torrents,  which  rush  down  the 
sides  of  the  mountains  with  the  force  of  cataracts,  and 
carry  with  them  enormous  quantities  of  rock,  which  is 
ground  up  by  degrees  into  the  finest  mud  and  poured 
into  the  Nile.  The  river  rises  so  much  in  consequence 
that  it  overflows  its  banks,  inundating  the  plains  of 
Lower  Egypt  during  four  months  of  the  year,  and 
wherever  the  flood  comes,  there  it  leaves  behind  it  a 
thin  film  of  rich  mud,  which  needs  but  little  labour  on 
man's  part  to  make  it  produce  most  abundant  harvests. 
So  large  is  the  amount  of  sediment  brought  down  by 
the  river — which  those  who  like  statistics  may  be  inter- 
ested to  know  is  about  equal  in  bulk  to  a  solid  cube 
measuring  more  than  five  feet  each  way  transported  in 
every  second — that  the  river-bed  is  gradually  rising,  and 
the  inundation  therefore  extends  further  and  further ; 
and  very,  very  slowly,  but  still  surely,  more  of  the 
desert  is  being  converted  into  fruitful  soil.  Left  upon 
the  Abyssinian  mountains,  the  materials  of  which  this 
sediment  is  composed  would  have  had  little  or  no  value 
— for  man's  purposes,  at  least — but,  transported  to  the 
magnificent  climate  of  Egypt,  and  mixed  with  other 
matter,  they  form  a  soil  which  is  the  very  perfection  of 
fertility. 

The  sediment  is  not  all  deposited  on  the  land  or  in  the 
river-bed,  however;  much  is  carried  into  the  Mediter- 
ranean, where  another  delta  is  being  gradually  formed, 


Soil-  Carriers  4  3 

equal  no  doubt  to  the  old  one  in  richness,  and  capable 
of  bearing  crops  as  abundant,  should  it  ever  rise  above 
the  waters.  A  delta  is  possible  only  where  there  is 
little  or  no  tide,  or  current,  to  carry  the  sediment 
away. 

But  it  must  not  be  forgotten  that  something  more 
has  been  done  than  merely  to  transport  this  wonderful 
soil.  It  has  also  undergone  much  mixing,  and  con- 
sists not  only  of  mud  washed  from  the  Abyssinian 
mountains  but  of  sand,  which  is  blown  into  the  river 
in  vast  clouds  from  the  desert.  The  Nile  itself,  too, 
has  done  a  great  deal  of  grinding,  and  sand-  and  mud- 
making,  as  well  as  its  tributaries.  Sand,  driven  by 
water,  will  wear  away  the  hardest  rock  by  degrees ; 
and  by  means  of  the  sand  which  the  wind  blows  into 
it,  the  river  has  cut  its  way  through  the  rocks,  scoop- 
ing out  for  itself  a  wide  deep  bed.  The  solid  mass  of 
rock  thus  removed,  grain  by  grain,  has  also  contributed 
in  no  small  degree  towards  the  formation  of  the  Great 
Delta. 

But  even   this  is   not  all.      No   soil  can   be  really, 
fertile,  however  rich  in  mineral  matter,  unless  it  con- 
tain  some   amount   of   animal   or  vegetable    matter. 
And  this,  too,  has  been  supplied  to  the  Delta  in  an 
interesting  and  remarkable  way. 

Nile- water,  like  that  of  all  rivers  more  or  less, 
contains  a  vast  number  of  microscopic  animals  and 
vegetables,  the  lowest  and  simplest  forms  of  life,  which 
are  not  only  left  behind  with  the  mud,  but  are  killed 
in  myriads  where  they  come  in  contact  with  salt  water. 
The  Mediterranean  being  a  tideless  sea,  this  wholesale 
destruction  cannot  take  place  except  at  the  mouth  of 
the  river,  and  for  a  certain  distance  beyond  it  in  the 


44  Soil- Carriers 

sea.  Fresh  water  being  lighter  than  salt,  flows  over 
the  latter  at  first,  before  the  two  mingle ;  and,  as  sea- 
water  abounds  in  these  minute  forms  of  life  to  a  much 
greater  extent  than  river-water  does,  and  as  fresh 
water  is  as  deadly  to  the  one  as  salt  to  the  other,  the 
destruction  wherever  the  two  come  in  contact  must  be 
wholesale. 

At  present  it  is  the  delta  of  the  future  which  chiefty- 
benefits;  but  the  present  delta  was  slowly  formed  in, 
like  manner  under  water,  and  has  therefore  received 
an  abundant  share  of  this  fertilizing  matter  in  ages 
past,  some  amount  of  which  is  also  brought  and  left 
with  the  mud  every  year. 

But  where  rivers  are  affected  by  the  tide,  there  the 
salt  water  flows  up  under  the  fresh,  for  many  a  mile 
above  their  mouths,  carrying  with  it  a  living  freight, 
which  must  to  a  large  extent  perish  and  be  left  behind ; 
while  the  microscopic  inhabitants  of  the  river-water 
are  destroyed  with  equal  certainty  wherever  they  come 
in  contact  with  that  which  is  salt,  or  even  brackish — 
that  is,  partially  salt. 

Hence  the  great  fertility  of  large  districts  on  both 
sides  of  the  Thames,  at  the  mouth  of  the  Humber,  on 
the  shores  of  the  Wash  and  Bristol  Channel. 

The  remarkably  productive  '  carses '  of  Scotland 
owe  their  fertility  to  the  same  apparently  insignificant 
cause;  and  the  soil  of  Holland  is  rich  for  similar 
reasons,  having  been  to  a  large  extent  formed  by  the 
Rhine,  Meuse,  and  other  rivers. 

The  whole  of  Southern  Louisiana,  with  its  extensive 
cotton  and  rice-fields,  was  made  in  like  manner  by  the 
Mississippi,  which  becomes  a  dense  yellow  torrent 
after  it  is  joined  by  the  Missouri,  and  brings  down 


Soil-Carrier  *  45 

with  it  a  heavy  load  of  mud,  ground  from  mountains 
3,000  miles  away,  which  it  has  deposited  in  some 
places  to  a  depth  of  300  feet. 

And  so  again,  on  a  smaller  scale,  the  low  plain  at 
the  head  of  the  Lake  of  Geneva  is  formed  of  mud  from 
the  mountains,  which  the  Rhone  has  brought  down 
and  deposited  in  the  lake,  adding  to  it  year  by  year, 
until  it  has  risen  above  the  water,  and  Port  Vallais, 
Which  stood  on  the  margin  of  the  lake  in  Roman  times, 
now  lies  a  mile  and  a  half  inland. 

Inundations  are  caused  usually  either  by  excessive 
rain,  such  as  that  which  falls  periodically  in  Abyssinia, 
or  by  the  melting  of  the  snow  in  spring  ;  but  passing 
mention  must  here  be  made  of  certain  inundations 
brought  about  by  very  different  causes,  and  which, 
though  on  a  very  much  smaller  scale  than  these  others, 
are  yet  said  to  have  altered  some  of  the  valleys  of 
North  America  to  a  quite  incredible  extent. 

These  inundations  have  been  caused  by  the  beaver. 
The  beaver  is  retreating  further  and  further  before 
man  ;  and  though  it  still  inhabits  the  North  of  Europe 
and  Asia,  it  is  nowhere  now  so  plentiful  as  here  in 
North  America,  where,  also,  the  effect  of  its  work  in 
the  past  may  best  be  observed. 

But  the  beaver  once  abounded  in  England  and 
Wales,  and  indeed  throughout  the  greater  part  of 
Europe,  as  the  names  of  many  places,  such  as 
Beverley,  Beverstone,  Biverbike,  and  many  others, 
plainly  show.  What  we  see  of  its  work  in  America, 
therefore,  is  probably  only  a  specimen  of  what  it  has 
done  wherever  it  has  been  undisturbed.  Here,  at  all 
events,  thousands  of  acres  of  land  have  been  sub- 
merged, at  one  time  and  another,  as  the  result  of  its 


46  Soil-Carriers 

labours.  As  is  well  known,  the  beaver  is  in  the  habit 
of  building  dams ;  and  these  are  often  so  solid  and 
extensive  as  to  stop  up  the  streams  and  rivers  in 
which  they  are  constructed,  causing  them  to  over- 
flow and  form  shallow  lakes. 

But  local  floods  were  only  the  first  result  of  its 
work;  for  the  streams  brought  down  with  them  the 
usual  sediment,  which  was  spread  over  the  inun- 
dated surface,  gradually  raising  its  level,  until  the  lake 
became  a  marsh  covered  with  marsh-plants.  Then, 
as  the  sediment  still  accumulated,  the  marsh-plants 
by  degrees  found  the  situation  too  dry  for  them,  and 
died  off;  their  places  were  then  taken  by  grasses,  and 
the  lakes  were  thus  converted  into  meadow  land, 
fertile,  as  river-formed  soils  usually  are,  and  enriched 
by  the  decay  of  the  marsh  plants. 

The  value  of  river-mud  is  abundantly  seen  in  Egypt ; 
and  in  Hungary  the  broad  river  Theisz  is  left  uncon- 
trolled by  dikes  in  its  upper  part,  because  the  yearly 
spring-floods  which  lay  the  whole  neighbourhood  under 
water,  though  inconvenient,  are  found  to  be  of  such 
great  benefit  to  the  soil. 

Rivers,  then,  must  be  reckoned  among  the  most 
important  makers  and  carriers  of  soil.  But  the  wind, 
too,  does  much  good  service,  though  also  occasional 
damage,  from  man's  point  of  view,  as  nature's  labourers 
are  apt  to  do,  in  these  disorganized  days. 

On  the  Lincolnshire  Wolds,  for  instance,  and  on  the 
coast  of  Norfolk,  where  the  soils  are  light  and  sandy, 
the  whole  of  the  finer  portion,  as  well  as  the  seed  sown, 
is  sometimes  altogether  blown  away  by  the  equinoctial 
gales.  One  field  near  Cromer  was  sown  three  times  in 
the  course  of  a  single  spring,  and  was  finally  left  to 


Soil-Carrier*  47 

itself,  all  the  upper  portion  of  the  soil  being  banked, 
like  a  snow-drift,  against  the  hedge. 

But  for  the  hedges  the  wind  would  no  doubt  have 
spread  the  soil  fairly  over  the  neighbouring  fields.  Its 
efforts  on  this  occasion  were,  however,  certainly  mis- 
directed. 

But  when  the  wind  is  able  to  raise  dust  from  the 
fields  high  in  the  air,  as  it  does  at  times,  it  may  carry 
it  great  distances — miles,  and  even  hundreds  of  miles 
— and  so  do  real  service  to  the  soil  elsewhere. 

There  is  naturally  most  dust  in  winter  and  early 
spring,  when  the  fields  are  bare,  more  or  less,  and 
especially  during  the  dry  March  winds.  Clouds  of 
dust  are  raised  from  ploughed  land,  and  in  dry  weather 
even  from  grass-land.  Large  quantities  are  transferred 
in  this  way  from  the  high  lands  to  the  lower. 

But  dust  may  be  blown  uphill  as  well  as  down,  and 
it  may  b^  carried  over  dry  sands,  or  absorbent  rocks, 
where  water  would  be  sucked  up  so  quickly  as  to  be  of 
no  use  as  a  carrier. 

It  has  been  suggested  that  much  of  the  fertility  of 
our  own  land  may  be  due  to  the  east  wind,  for  which 
few  people  have  a  good  word  to  say.  The  east  wind  is 
a  dry  wind,  and  undoubtedly  a  dusty  wind,  as  we  know 
it ;  but  when  the  climate  was  colder  it  must  have  been 
sharper,  and  drier,  and  dustier  still ;  and  it  may  well  be, 
therefore,  that  it  has  helped  to  bring  about  that  mixture 
of  the  soils  to  which  they  owe  their  fertility. 

As  to  the  enormous  distances  which  fine  dust  is  often 
carried,  we  have  positive  proof  in  the  brick-red  or 
cinnamon-coloured  sirocco  dust  which  falls  thickly  upon 
vessels  in  the  Atlantic  at  certain  seasons  of  the  year, 
and  is  carried  to  Europe  as  far  inland  as  the  Tyrol. 


48  Soil-Carriers 

This  dust,  which  is  exceedingly  fine,  has  travelled 
thousands  of  miles  on  the  wings  of  the  wind,  the  greater 
part  of  it  having  been  borne  across  the  Atlantic  from 
the  banks  of  the  Orinoco  and  Amazons.  Its  value  as  a 
fertilizer  is  recognised  by  the  North  American  farmers, 
who  use  a  similar  deposit  of  '  flint-earth '  to  mix  with 
some  of  their  heavy  soils.  Very  fertilizing  also  must  be 
the  volcanic  dust,  which,  being  carried  high  up  into  the 
air,  at  times  probably  far  above  the  cloud-region,  is 
conveyed  enormous  distances  before  it  finally  sinks  to 
the  earth. 

The  most  tremendous  volcanic  outburst  on  record  is 
that  of  Krakatoa  in  1883,  when  millions  of  tons  of 
matter  were  hurled  into  the  upper  air,  and  dust,  to 
the  depth  of  two  inches,  fell  a  thousand  miles  off. 
The  vegetation  of  the  neighbourhood  was,  of  course, 
utterly  destroyed,  being  deeply  buried  in  ashes  and 
pumice-dust;  but  the  great  farm  is  so  extensive  that 
occasional  ruin  here  and  there  is  of  little  moment 
compared  with  the  benefits  which  follow  in  the  long 
run,  especially  when  the  ravages  made  are  so  quickly 
repaired  as  they  sometimes  are.  In  this  instance  it 
took  less  than  five  years  to  cover  up  the  dismal  scene 
of  desolation  with  a  fresh  growth  of  tropical  luxuriance. 
Just  so  Vesuvius  is  said  to  smother  and  destroy  the 
crops  in  its  neighbourhood  every  eighth  year ;  but  it  is 
this  very  fact  which  makes  the  soil  so  wondrously 
fertile  during  the  other  seven. 

However,  we  are  concerned  just  now  chiefly  with 
the  work  done  by  the  wind,  and  must  glance  at  one 
curiously  interesting  sample  of  it  which  has  been 
observed  in  the  valley  of  the  Limagne,  in  Auvergne. 
Here  there  is  no  active  volcano  to  furnish  dust,  and 


Soil-Carriers  49 

• 

yet  the  fields  seem  to  get  it — and  that,  too,  without  the 
drawback  of  being  suffocated  every  few  years.  Where 
does  it  come  from  ? 

The  wind  blows  chiefly  from  the  west  and  south- 
west, across  the  mountain-chain  of  the  Domes.  The 
air  on  the  western  side  of  the  mountains  is  bright  and 
clear,  but  that  on  the  Limagne  side  is  generally  slightly 
hazy,  and  the  haze  seems  to  consist  of  fine  dust.  And 
when  we  inquire  about  the  mountains,  we  find  that 
they  are  extinct  volcanoes,  and  are  widely  strewn  with 
volcanic  ashes,  the  relics  of  ancient  eruptions,  rich  in 
the  minerals  which  make  the  most  fertile  soils,  and 
just  in  the  condition  in  which  plants  can  most  readily 
make  use  of  them. 

It  seems,  therefore,  that  the  inexhaustible  fertility  of 
the  Limagne  is  in  great  part  due  to  these  constant 
supprfes,  which  are  carried  across  the  country  by  the 
sometimes  severe  wind,  and  naturally  fall  when  it  sub- 
sides, besides  being  brought  down  by  rain  and  snow. 

The  English  proverb  declares  that '  a  peck  of  March 
dust  is  worth  a  king's  ransom/  and  there  can  be  no 
doubt  that  the  clouds  of  dust  blown  upon  the  fields 
from  the  high-roads  are  most  valuable.  So,  too,  in 
spite  of  all  their  drawbacks,  are  the  dust-storms  which 
occur  from  time  to  time  in  certain  regions — as,  for  in- 
stance, in  Western  Iowa,  where  the  air  is  filled  for 
days  together  with  dust  of  the  finest  description. 


V. 

SOIL-BINDERS 

THE  materials  being  ground  up,  mixed,  and  in  some 
cases  transported,  there  are  still  two  important  matters 
to  be  attended  to  before  anything  strictly  to  be  called 
'  soil '  can  be  formed. 

First,  these  materials  have  to  be  bound  to  the 
spot  where  they  have  been  deposited ;  and,  secondly, 
before  they  can  grow  any  but  poor  crops  they  in 
many  cases  need  the  addition  of  animal  or  vegetable 
matter. 

Nile-mud,  and  river-mud  in  general,  already  con- 
tains some  proportion  of  this,  and  does  not  consist  of 
mineral  matter  only. 

But  the  first  thing  is  to  make  the  future  soil 
settle  down,  since  nothing  of  value  can  grow  in  a 
wandering  sand-drift.  The  deposits,  whatever  they 
be,  need  protection  against  the  washing  of  the  rain 
and  the  drying  of  the  wind,  which  will  not  only  dry 
the  surface,  but  blow  it  away  in  clouds  if  it  is  left 
exposed. 

Even  to  this  day  the  plains  of  Hungary  suffer  from 
dust-storms,  though  they  have  long  been  covered  with 
vegetation ;  and  we  may  easily  imagine  how  much 


Soil-Binders  51 

worse  these  must  have  been  when  sun  and  wind  had 
full  play,  with  nothing  to  check  fchem. 

It  is  clear,  too,  that  where  sand  or  volcanic  ashes 
have  been  brought  by  the  wind,  the  same  wind  may 
in  many  instances  scatter  them  again.  And  where 
mud  has  been  brought  down  by  a  river  and  deposited 
within  reach  of  the  tide,  there  it  will  be  liable  to  be 
washed  away,  unless  some  means  be  taken  to  fix  it  to 
tlie  spot. 

Let  us  even  look,  for  instance,  at  a  railway  embank- 
ment. It  has  been  piled  by  human  hands  with  a 
special  object,  and  is  a  far  more  solid  mass  than  if  it 
had  been  merely  blown  together ;  but  yet  it  to  some 
extent  wastes  away.  Its  bare,  exposed  surface  is 
washed  and  wasted  by  the  rain,  dried  and  blown  away 
by  the  wind  ;  for  there  is  nothing  to  protect  it  from 
either^to  begin  with.  But  this  state  of  things  does  not 
last  long.  There  is  always  plenty  of  seed  floating  in 
the  air,  ready  to  sow  itself  on  any  bare  space  it  can. 
find ;  so  that  in  two  or  three  years'  time  the  embank- 
ment is  overgrown  with  grass,  whose  roots  are  so 
matted  together  that  further  shifting  of  the  soil  is  to  a 
large  extent  prevented. 

Of  course,  where  seed  is  sown  even  before  the  soil  is 
made,  as  we  have  seen  in  the  case  of  lichens,  there  the 
mould  as  it  is  formed  is  kept  in  place  and  protected, 
and  is  able  to  deepen  undisturbed.  But  where  sand 
has  been  heaped  together  by  the  wind,  or  .mud  de- 
posited on  the  coast,  there  something  is  needed  to  give 
it  firmness,  or  else  it  will  be  dispersed  again. 

The  sandhills  on  the  plains  of  Venezuela,  for  example, 
are  still  constantly  moving  to  and  fro,  here  to-day  and 
there  to-morrow,  except  in  one  district  where  they 


52  Soil- Binders 

have  been  consolidated  into  a  low  range  of  permanent 
hills  by  a  curious  grass  with  tall,  cutting,  sword-edged 
blades,  which  grows  so  closely  and  with  such  rapidity 
that  any  paths  made  by  travellers  are  quite  covered  up 
and  destroyed  by  it  in  a  few  days.  In  itself  it  is  of  no 
use — that  is,  it  cannot  be  used  as  fodder  for  flocks  or 
herds,  though  no  doubt  it  affords  shelter,  and  possibly 
food,  to  wild  animals ;  and  where  it  grows,  there  other 
more  useful  plants  have  no  chance,  being  simply  over- 
powered and  choked  by  it. 

But  then  useful  grasses  and  other  fodder-plants  would 
be  quite  unable  to  spring  up  while  the  sand  was  shift- 
ing about ;  they  could  not  grow  fast  enough  to  stop  it 
from  smothering  them.  Their  turn  may  come  by-and- 
by,  when  generations  of  this  coarse  grass  have  improved 
the  soil. 

The  plants  which  are  most  useful  for  this  work  of 
binding  the  soil  and  giving  it  its  first  firmness  are  those 
which,  besides  growing  quickly,  also  send  out  especially 
long  roots,  runners,  or  underground  stems,  often  mis- 
called roots,  which  are  pegged  down  at  frequent  in- 
tervals by  real  roots,  much  in  the  same  way  as  the 
thatcher  binds  down  the  straw  on  the  rick-top.  The 
couch-grass  and  others  have  long  underground  stems 
of  this  sort,  as  the  gardener  knows  to  his  sorrow ;  and 
then  there  are  the  bindweeds,  most  appropriately  so 
named,  for  they  send  out  long,  trailing  runners  above- 
ground,  having  roots  at  each  joint,  which  make  them 
extremely  difficult  to  get  rid  of  when  once  they  have 
established  themselves  in  a  garden.  Their  tropical 
relatives,  the  ipomseas — plants  of  much  larger  growth, 
but  bearing  similar  convolvulus-blossoms  of  more  bril- 
liant colour— are  among  the  plants  which  render  most 


Soil-Binders  53 

useful  service  in  the  Bermudas  by  stopping  the  fine 
white  coral-sand  of  the  coast  from  invading  and  bury- 
ing the  neighbouring  gardens. 

Plants  of  the  convolvulus  family  are  equally  useful 
on  the  coast  of  Ceylon,  where  the  rivers,  flowing 
rapidly  down  from  lofty  hills,  bring  with  them  heavy 
loads  of  sand  and  mud.  Under  ordinary  circumstances, 
since  the  Bay  of  Bengal  is  not,  like  the  Mediterranean, 
a  tideless  sea,  these  would  be  carried  away  and  de- 
posited some  miles  from  the  coast.  But  this  is  pre- 
vented by  the  ocean-currents,  which  set  towards  the 
island,  and  not  only  drive  back  what  the  rivers  bring 
down,  but  add  to  them  similar  loads  of  their  own. 
Accordingly,  the  sand  and  mud  of  the  rivers,  unable  to 
escape  further,  are  piled  up  in  bars  along  the  shore, 
and  these,  when  once  begun,  rapidly  increase  in  size 
until  they  rise  above  the  water,  and  form  long  em- 
bankments reaching  for  many  miles,  with  the  river 
flowing  behind,  and  occasionally  bursting  through 
them. 

These  bars,  though  a  mile  or  two  and  even  more  in 
width,  are  not  very  solid  at  first,  but  they  are  presently 
sown  with  such  plants  as  do  not  mind  salt  water,  and 
the  roots  soon  penetrate  and  mat  together  in  such  a 
way  as  to  prevent  the  soil  being  washed  away.  The 
drier  sand  on  the  top  of  the  bank  is  protected  from 
wind  and  rain  by  creeping  plants,  among  which  is  one 
of  the  great  bindweeds  already  mentioned,  which  covers 
the  surface  down  to  the  water's  edge,  with  its  long, 
trailing  branches  pegged  down  at  each  joint,  as  already 
described. 

When  the  sand  has  been  consolidated  and  improved 
by  the  growth  and  decay  of  these  and  such-like  plants, 


54  Soil-Binders 

there  follow  shrubs  and  small  trees,  such  as  do  not 
object  to  the  saltness  of  the  soil;  and  finally,  when  the 
way  has  been  carefully  prepared,  the  once  barren 
sand-banks  are  covered  with  groves  of  coco-palms. 
It  is  a  fact  never  to  be  lost  sight  of,  that  here,  as  so 
frequently  elsewhere,  the  first  all-important  work  is 
done  by  comparatively  feeble  instruments;  the  dust- 
like  lichen  prepares  the  way  for  the  pine,  and  the 
insignificant  salt-worts,  and  weak-stemmed,  creeping 
bindweeds  make  ready  for  the  palm.  The  pine  could 
not  have  found  foot-hold  or  sustenance  on  the  granite, 
nor  the  palm  on  the  sand-bank,  but  for  these  indis- 
pensable fore-runners. 

The  mangrove,  like  the  coco-palm,  thrives  in  salt 
water,  but  is  unlike  it  in  being  able  to  grow  without 
any  preparation,  and  itself  does  much  to  consolidate 
the  mud  in  which  it  grows.  A  mangrove-swamp  is  not, 
by  all  accounts,  a  delightful  place,  and  is  strongly 
suggestive  of  malaria  and  fever,  but  it  must  be  regarded 
as  only  a  first  step  towards  arresting  and  cultivating 
the  mud  in  many  tropical  regions. 

The  mangrove  is  a  low-growing  tree  with  widely- 
spreading  branches,  and  is  wonderfully  adapted  by  its 
peculiarities  to  the  situations  in  which  it  grows.  It  is 
found  on  many  tropical  coasts,  growing  between  high 
and  low  water-mark,  and  in  river  estuaries  washed  by 
the  sea  during  one  part  of  the  day,  and  left  exposed 
during  another.  From  its  branches  it  sends  down 
long  roots  which,  on  reaching  the  mud,  fix  themselves 
firmly  in  it,  and  become  independent  trees ;  and  the 
seed,  which  begins  to  germinate  and  grow  while  still  in 
the  fruit  and  on  the  bough,  also  sends  out  branches 
and  roots  sometimes  long  enough  if*  touch  the  ground, 


Soil-Binders  55 

before  it  falls.  The  fruit-roots,  branch-roots  and  stems, 
together  form  a  tough,  closely-woven  net-work,  in  which 
the  mud  of  the  river  is  caught  and  entangled,  and 
converted  into  solid,  or  something  like  solid,  land,  very 
much  more  quickly  than  it  would  be  without  their 
help. 

In  Holland,  the  people  have  taken  a  leaf  out  of 
nature's  book,  and  carefully  plant  the  sea-dikes,  on 
which  the  very  existence  of  their  land  depends,  with 
the  'sharp  rush,'  whose  multitude  of  roots  mat  to- 
gether near  the  surface,  besides  striking  deep  into  the 
soil. 

The  horse-tails,  too,  which  thrive  there  to  such  an 
extent  that  we  used  to  import  them  under  the  name 
of  Dutch  rushes,  have  underground  stems  of  extra- 
ordinary length,  and  so  much  interlaced  that  they 
seem  exactly  intended  to  bind  the  loose  soil. 

Then  there  is  the  sea-sedge,  an  insignificant  little 
grass-like  plant,  but  a  few  inches  high,  which  does  not 
look  capable  of  much  at  first  sight.  But  it  grows  with 
marvellous  rapidity — always  an  important  advantage 
where  loose  sand  is  concerned — and  it  covers  extensive 
tracts  in  a  very  short  space  of  time,  sending  out,  only 
just  below  the  surface,  long,  creeping  stems,  which  are 
firmly  pinned  down  by  frequent  root-fibres. 

The  growth  of  the  sea-reed  is  even  more  remark- 
able. It  will  grow  in  the  very  driest  soil,  and  has 
been  planted  in  the  Hebrides  to  cure  sand-drift.  Its 
runners  are  often  as  much  as  twenty  feet  long,  and 
so  tough  and  strong  that  they  have  been  used  for  rope- 
making. 

Some  quite  fragile-looking  roots  are  indeed  remark- 
ably tough,  and  capable  of  resisting  an  immense  strain 


56  Soil- Binders 

without  breaking.  The  roots  of  the  Lucerne  clover 
are  said  to  be  often  as  strong  as  those  of  an  ash-tree, 
though,  of  course,  very  much  finer,  and  looking  much 
weaker;  and  they  have  at  times  given  unmistakable 
proof  of  their  strength,  not  merely  by  resisting  the 
advance  of  the  ploughshare,  but  by  actually  break- 
ing it. 

It  is  this  wonderful  tenacity  which  makes  roots  so 
useful  in  binding  the  soil  together,  and  in  keeping  the 
banks  of  streams  and  rivers,  as  well  as  sea-dikes,  from 
being  seriously  undermined. 

On  mountain  slopes,  too,  the  roots  of  trees  and 
brushwood  serve  to  keep  in  its  place  the  soil  which 
must  else  slip  down  by  its  own  weight,  even  if  there 
were  no  rain  to  wash  or  wind  to  blow  it.  And  where 
people  have  been  so  short-sighted  as  to  cut  down 
mountain  forests,  there  they  have  had  to  lament 
not  merely  the  ruin,  but  the  actual  loss,  of  the  fields 
in  their  vicinity,  which  have  been  carried  bodily 
away. 

In  some  parts  of  the  French  Alps  half  the  cultivated 
ground  has  been  washed  away,  owing  to  the  reckless 
destruction  of  the  pines ;  and  this  is  not  all,  for  when 
the  forests  are  gone,  not  only  does  the  soil  follow,  but 
so  do  the  avalanches ;  or  rather  they  come, !  plunging 
down  from  the  heights  above  and  overwhelming  every- 
thing in  their  way.  The  trees,  and  the  trees  only, 
were  strong  enough  to  resist  them. 

It  is  remarkable  what  a  very  slight  obstacle  is  often 
enough  to  stop  the  onward  motion  of  a  sand-drift,  a 
few  oleanders,  by  no  means  very  sturdy  shrubs,  being 
often  found  sufficient  for  the  purpose  in  the  Bermudas. 
A  sand-drift  cannot,  of  course,  compare  with  an 


Soil- Binders  57 

avalanche,  but  it  has  also  been  found  possible  to  stop 
formidable  snow-drifts  by  means  of  rose  trees  ! 

In  the  wide  plains  of  South  Hungary,  where  the 
wind  has  nothing  to  break  its  force,  the  railway  lines 
are  often  in  winter  blocked  with  snow-drifts,  which 
there  seemed  to  be  no  means  of  preventing,  until  in 
one  part  the  experiment  was  tried  of  planting  hedges 
of  Provence  roses  on  each  side.  The  hedges  are 
of  the  height  of  a  tall  man,  and  the  lines  were  kept 
clear  during  some  exceptionally  heavy  falls  of  snow  a 
few  years  ago  where  they  were  invariably  blocked 
before. 

On  the  south-west  coast  of  France  there  is  an 
extensive  sandy  region  known  as  the  Landes,  which  at 
one  time  seemed  likely  to  be  converted  into  a  veritable 
Sahara,  and  was  saved  from  this  fate  by  nothing  else 
but  the  planting  of  pines. 

It  is  a  sandy  region  still,  and  the  fine  dust  arising 
from  it  in  windy  weather  gives  it  the  appearance  of 
being  overhung  with  clouds.  The  sand  rattles  inces- 
santly against  the  carriage-windows  as  the  train 
advances  southwards;  but  in  the  last  century  the 
sand-dunes  were  always  in  motion,  constantly  changing 
their  places,  ebbing  and  flowing  like  the  tide,  but 
creeping  gradually  further  and  further  inland.  When 
the  storm -wind  blew  from  the  west  it  caught  up 
the  sand  and  scattered  it  over  the  adjacent  country, 
where  it  fell  like  volcanic  ashes,  doing  equal  damage 
and  none  of  the  good,  for  it  consists  to  a  large  extent 
of  fine  white  quartz,  the  most  hopelessly  barren  sand 
there  is. 

In  ancient  times  this  district  is  said  to  have  been 
fairly  well  covered  with  oak  woods,  remains  of  which 


58  Soil- Binders 

are  yet  to  be  seen  ;  why,  and  when,  they  were  destroyed 
seems  to  be  unknown,  but  the  results  were  disastrous 
and  even  alarming.  At  length,  however,  the  happy 
thought  came  to  an  engineer  named  Bre'montier,  in 
1787,  that  where  trees  had  grown,  trees  might  be 
induced  to  grow  again,  and  the  attempt  was  made, 
not  with  oaks,  for  they  could  not  have  borne  the  sand, 
but  with  the  maritime  pine.  Over  and  over  again  it 
was  tried  and  failed,  owing  to  the  shiftiness  of  the  sand ; 
but  at  length,  by  dint  of  immense  perseverance,  the 
seed  was  induced  to  take  root,  and  then  the  worst  of 
the  battle  was  over. 

The  pine-roots  spread  little  by  little,  entangling  the 
sand  and  putting  a  stop  to  further  rovings ;  one  dune 
after  another  was  brought  to  a  standstill,  and  that 
which  threatened  to  become  a  desert  has  gradually 
been  converted  into  profitable  pine-woods,  with  inter- 
mediate stretches  of  vigorous  heather  and  furze  ten  feet 
high,  and  here  and  there  a  thick  growth  of  hawthorn 
and  holly. 

We  may  conclude  this  chapter  by  mentioning  the 
curious  origin  ascribed  to  certain  patches  of  grass 
which  occur  frequently  all  over  the  bison  region  of 
North  America.  These  patches  are  said  to  be  evidently 
due  to  the  bison's  habit  of  wallowing  in  the  dust,  and 
were,  in  fact,  the  wallowing  places  of  the  herd.  The 
repeated  wallowing  of  a  number  of  animals  created 
shallow  hollows  or  depressions  which  the  rain  converted 
into  pools,  where  the  water  lingered  and  into  which  it 
drained  from  the  surrounding  soil.  Even  when  the 
water  had  drained  away  the  hollows  would  continue 
damp  for  some  time,  and  grass-seeds  falling  upon  them 
would  readily  spring  up.  The  grass-plants  would 


Soil-Binders  59 

speedily  weave  a  network  of  roots  over  the  whole, 
forming  in  time  a  thick  mat  by  which  the  soil  would 
be  effectually  held  together  and  consolidated,  and  the 
bison  who  wanted  a  dust  bath  in  future  would  have  to 
choose  a  fresh  wallowing  place  for  himself  and  his 
companions.  But  the  soil  would  have  been  won  for 
vegetation,  and,  once  covered  with  green  things,  it 
would  not  easily  be  given  up  again. 


CHAPTER  VI. 

FIELD -LABOURERS 

THE  field-labourers,  whose  work  we  are  going  first  to 
look  at,  are  somewhat  rough  in  their  ways,  it  must  be 
confessed,  and  not  such  as  the  farmer  generally  cares 
to  see  at  work  upon  his  land.  For  when  he  has  taken 
possession  of  the  beds  of  soft  earth  ready  prepared  for 
him,  his  ploughs  and  harrows  come  in  very  usefully, 
and  he  is  of  opinion  that  he  can  manage  the  tillage  of 
his  fields  himself. 

Nature,  however,  has  no  steel  ploughs,  and  her  fields 
must  be  tilled  by  other  means,  for  they  need  it  as  well 
as  the  farmer's.  And  her  labourers  work  in  all  parts 
of  the  farm,  giving  man  a  vast  amount  of  help,  for 
which  he  is  often  not  as  grateful  as  he  might  be,  for  he 
and  they  do  not  at  present  understand  one  another ; 
and  though  he  may  tame  a  lion  he  cannot  control  a 
worm. 

But  though  they  may  often  be  troublesome  where 
man  has  taken  possession,  it  is  to  the  long-continued 
services  of  some  of  these  natural  labourers  that  he 
owes  much  of  the  fruitfulness  of  some  of  his  richest, 
lands. 

The  wonderful  fertility  of  the  lands  in  Manitoba 


Field- Labourers  61 

for  instance,  is  due,  not  only  to  the  fineness  of  the 
soil,  but  to  the  long  ages  of  undisturbed  animal  and 
vegetable  life  by  which  it  has  been  deepened  and  en- 
riched. 

Every  now  and  again,  perhaps,  there  has  been  a 
prairie  fire,  laying  waste  wide  tracts  of  country,  but 
leaving  a  large  supply  of  most  valuable  ashes  behind  ; 
and  of  the  value  of  ashes  as  a  manure,  the  farmers 
of  Flanders  have  so  high  an  opinion  that  they  say, 
'  He  who  spends  nothing  on  ashes  is  sure  in  the 
end  to  pay  double.'  Season  by  season,  too,  leaves 
have  fallen,  and  annuals  have  withered  and  decayed, 
adding  their  remains  to  those  of  countless  former 
generations. 

No  soil  is  really  fertile,  whatever  the  mineral  matter 
composing  it,  unless  it  also  contain  some  amount  of 
organic  matter — matter  derived  from  organized,  living 
things,  whether  animal  or  vegetable.  Organic  matter 
alone  is  not  enough  to  make  a  fertile  soil ;  but  with 
less  than  one-half  per  cent,  of  organic  matter,  no 
soil  can  be  cultivated  to  much  purpose.  Even  with 
this  quantity  it  will  not  grow  corn  of  any  kind 
successfully,  but  it  will  grow  wild  crops  with  less ; 
and  these  in  time  add  what  is  required,  if  they  are 
let  alone  for  many  generations.  The  Black  earth  of 
Russia,  which  is  jet  black  when  wet  and  brown 
when  dry,  owes  its  colour  and  much  of  its  fertility 
to  the  finely  divided  and  well-mixed  vegetable  matter 
which  it  contains,  the  remains  of  countless  genera- 
tions of  wild  plants,  which  held  undisturbed  posses- 
sion there  for  ages,  but  have  now  made  way  for  their 
betters. 

AH  soils  contain  some  amount  of  organic  matter, 


62  Field- Labourers 

animal  or  vegetable,  but  chiefly  vegetable ;  and  this  is 
true  even  of  such  as  seem  to  consist  only  of  sand,  clay, 
or  chalk.  For  wherever  it  is  possible  for  a  plant  to 
grow  at  all,  thither  something  suited  to  the  situation 
is  sure  to  find  its  way.  The  wild  crop  may  be  a  very 
poor  one,  perhaps  only  some  coarse,  wiry  kind  of 
grass — for  there  is  hardly  any  soil  so  poor  but  that 
grass  of  some  kind  will  grow  in  it — and  when  this  has 
improved  the  soil  a  little,  other  better  sorts  may 
follow. 

The  Black  earth  is  of  a  very  dark  colour  even  when 
dry;  but  it  is  not  always  so  easy  as  in  this  case  to 
judge  of  a  soil  by  its  appearance.  Sometimes  the 
organic  matter,  being  only  imperfectly  decayed,  may 
be  visible  enough  ;  sometimes  it  may  be  reduced  to  a 
fine  brown  powder ;  in  some  cases  it  may  have  more 
or  less  entirely  lost  its  colour;  and  then,  again,  it 
may  be  so  thoroughly  decayed  as  to  be  even  soluble 
in  water. 

Whether  visible  or  not,  however,  there  it  surely  is  in 
every  soil,  in  larger  or  smaller  quantities. 

But  it  is  the  effect  of  animal  life  that  we  are  now  to 
look  at.  Animals,  large  and  small,  benefit  the  land  by 
manuring  it ;  but  this  is  so  obvious  a  benefit  that  we 
need  not  dwell  upon  it  further  than  to  remark  that 
coprolites — the  fossilized  droppings  and  bones  of 
animals  of  former  ages — and  guano,  the  droppings  of 
birds,  are  among  the  most  valuable  manures  which  the 
farmer  can  use,  and  where  they  are  not  to  be  had  upon 
the  spot  he  finds  it  worth  his  while  to  bring  them  from 
a  distance.  When,  therefore,  we  consider  the  abundant 
animal  life  which  for  ages  occupied  many  of  the  lands 
now  brought  under  the  plough,  we  can  understand  one 


Field- Labourers  63 

cause  of  their  fertility — they  have  been  regularly 
manured  for  ages. 

But  besides  manuring  the  land  during  their  lives,  the 
animals  must  have  left  their  bones  to  enrich  it  also, 
whenever  they  escaped  being  devoured.  Small  dead 
bodies  must  have  been  covered  up  by  leaves,  or  buried, 
as  we  shall  see,  either  by  the  castings  thrown  up  by 
worms  or  by  the  burying  beetles,  whose  office  it 
especially  is  to  act  the  part  of  sexton  to  the  smaller 
wild  animals. 

Burrowing  animals  have  also  been  especially  useful 
in  more  ways  than  one.  In  the  first  place,  they  have 
added  to  the  organic  matter  of  the  soil,  and,  in  the 
second,  to  the  mineral  matter  also ;  and  besides  this 
they  have  done  much  to  drain  the  soil,  and  expose  it 
to  the  influences  of  the  sun  and  air. 

The  organic  matter  which  they  have  added,  besides 
their  own  droppings,  consists  of  the  materials  which 
they  use  to  line  their  nests,  principally  leaves  and 
grass,  and  also  the  remnants  of  their  food,  nuts, 
grain,  acorns,  and  sometimes  the  whole  of  their  winter 
stores. 

They  have  added  also  to  the  mineral  matter  of  the 
soil  by  helping  on  the  decay  of  the  underlying  rocks. 
These  are  seldom  at  any  great  depth  beneath,  for  the 
loose  materials  with  which  they  are  covered  are  but  as 
a  film  of  dust  compared  with  the  thickness  of  the  solid 
mass.  The  soil  at  its  very  thickest  is  measured  only 
by  feet,  while  the  solid  crust  of  the  earth  is  measured, 
at  least,  by  hundreds  of  miles ;  and  in  most  cases  the 
soil  is  actually  only  a  few,  often  a  very  few,  feet 
thick. 

Burrowing  animals  often  carry  their  tunnels  down. 


64  Field-Labourers 

several  feet,  and  in  this  way  make  it  easier  for  the  rain 
and  the  air  to  reach  the  rock  below;  and  wherever 
these  penetrate,  there,  as  has  been  already  shown, 
decay  must  surely  follow,  slowly  or  rapidly,  according 
to  the  nature  of  the  rock.  In  this  way,  therefore, 
burrowing  animals,  whether  rabbits,  ground  squirrels, 
or  even  worms,  have  helped  to  deepen  the  soil ;  and 
by  the  lives  and  labours  of  these  and  similar  animals, 
long  continued,  some  of  the  most  fertile  lands  have 
been  prepared. 

We  will  now  look  at  their  work  more  in  detail. 
All  over  the  Pampas  of  South  America  there  are 
frequent  groups  of  holes  excavated  by  the  bizcacha,  a 
curious,  rabbit-headed  animal,  as  large  as  a  badger ; 
and  in  South  America  also,  but  chiefly  in  the  moun- 
tain valleys,  dwells  the  bright-eyed,  soft-furred  little 
chinchilla,  not  much  larger  than  a  squirrel,  whose 
burrows  are  found  together  in  such  large  numbers  as 
to  cause  almost  as  much  inconvenience  as  those  of  the 
bizcacha. 

In  the  western  regions  of  North  America,  from 
Mexico  to  the  Arctic  Ocean,  as  well  as  in  the  northern 
parts  of  the  Old  World,  there  are  a  large  number  of 
small  animals  called  by  the  general  name  of  '  ground- 
squirrels,'  and  resembling  tree  -  squirrels  in  many 
respects,  though  some  of  their  habits  are  very  dif- 
ferent. Like  the  tree-squirrels,  they  lay  up  stores 
of  food,  but,  unlike  them,  they  burrow  in  the  ground, 
and  live  together  in  large  villages  instead  of  in 
pairs. 

One  of  these,  the  Chipmunk  or  Hackee,  abounds  in 
parts  of  North  America,  where  it  makes  very  extensive 
excavations,  considering  its  size,  which  is  less  than  that 


Field- Labourers  65 

of  a  tree-squirrel.  It  has  a  large  nest  lined  with  leaves 
and  grass;  and  the  storehouses  of  one  burrow  have 
been  found  to  yield  a  grand  supply  of  food— a  quart  of 
hazel-nuts,  nearly  a  peck  of  acorns,  two  quarts  of 
buckwheat,  and  smaller  quantities  of  other  vegetable 
food. 

The  Prairie-dog,  of  the  same  family,  is  rather  larger, 
and  something  between  a  squirrel  and  a  marmot  in 
appearance.  Its  *  villages,'  '  towns,'  or  warrens  cover 
many  square  miles,  and  in  some  parts  are  so  extremely 
numerous  as  to  have  undermined  extensive  tracts  of 
pasture-land,  much  to  the  inconvenience  and  danger  of 
horses,  not  to  mention  their  riders. 

The  dog-towns,  so-called,  are  ruled  by  a  '  big-dog, J 
who  sits  on  a  mound  in  front  of  his  burrow,  apparently 
directing  the  affairs  of  the  community. 

The  Gopher,  or  Canada  pouched-rat,  too,  is  to  be 
found  in  the  prairie,  where  it  dwells  not  merely  in 
thousands,  but  in  hundreds  of  thousands,  and  has  so 
completely  taken,  perhaps  we  should  rather  say  kept, 
possession,  that  in  some  parts  other  quadrupeds  are 
almost  excluded.  The  Gophers  extend  over  hundreds 
of  thousands  of  square  miles,  and  have  honey-combed 
millions  of  acres.  One  may  indeed  ride  for  days 
and  even  weeks  through  some  districts,  finding  them 
everywhere  as  plentiful  as  if  the  whole  district 
were  one  vast  warren.  If  ever  the  lands  should  be 
settled,  the  first  husbandmen  will  have  a  hard  fight 
for  possession  with  the  present  owners,  whose  diligence 
in  burrowing  is  wonderful,  for  they  work  both  night 
and  day,  though  they  do  not  go  nearly  as  deep  as  the 
'dogs.' 

The  burrows  will  just  admit  a  man's  arm  at  the 

5 


66  Fie  Id- Labourers 

mouth,  growing  narrower  farther  down,  but  they  make 
up  in  numbers  for  what  they  lack  in  size.  Each  Gopher 
lives  alone  in  a  burrow  of  its  own  ;  there  are  separate 
burrows  to  hold  the  winter  stores,  and  large  numbers 
seem  to  be  made  either  for  temporary  refuges,  or  from 
a  pure  love  of  digging  which  can  never  be  satisfied,  for 
the  deserted  burrows  are  many  more  than  can  be 
accounted  for  by  the  size  of  the  colonies. 

Other  burrowers,  better  known  in  the  Old  World, 
are  the  marmots,  which  make  very  large  and  rather 
complicated  burrows,  and  have  quite  riddled  the  rocks 
in  Turkestan,  in  some  parts  of  which  they  abound; 
and  others  again  of  the  same  great  family  of  rodents, 
or  'gnawers/  the  Gerboas,  have  honey-combed  the 
sides  of  mountains  in  South  Africa,  and  possess  such 
strong  teeth  that  in  the  north  they  even  gnaw  through 
the  thin  layer  of  stone  beneath  the  sand,  and  thus  do 
some  of  the  very  first  work  of  the  pioneer  labourers. 

Every  country,  indeed,  seems  to  have  its  special 
burrower  or  burrowers,  and  everywhere  their  work  has 
similar  results,  often  troublesome  enough,  where  man 
has  established  himself,  but  doing  a  useful  and  im- 
portant part  of  the  work  of  the  farm,  of  which  man 
reaps  the  benefit  in  after  years. 

In  England  the  field  burrower  with  which  we  are 
most  familiar,  unpleasantly  familiar,  too,  is  the  common 
mole.  No  matter  where  he  lives,  the  mole's  labours  are 
not  anywhere  looked  at  with  a  friendly  eye  by  farmer 
or  gardener;  and  so  fierce  is  the  war  waged  against 
him  that  it  is  matter  for  wonder  how  he  has  managed 
to  escape  extermination.  Mole-catchers  boast  of  having 
slain  many  tens  of  thousands,  one  declaring  that  he 
had  trapped  twelve  hundred  in  six  months.  Yet  still 


Field- Labourers  67 

the  mole  lives  on ;  lives  and  labours,  as  some  say,  in 
the  service  of  ungrateful  man. 

The  sins  alleged  against  him  are :  that  he  drains  the 
soil  so  thoroughly  by  his  network  of  underground 
galleries  as  to  render  it  dry  and  barren ;  that  he 
damages  the  crops  by  uprooting  them,  and  by  ex- 
posing, destroying,  or  eating  their  roots ;  and,  finally, 
that  he  uses  such  a  large  quantity  of  spring  corn,  as 
much  as  a  couple  of  hundred  blades,  to  make  his 
bed,  that  where  he  abounds  one-eighth  of  the  crop  is 
lost. 

These  are  serious  accusations ;  but  the  mole  is  not 
without  friends,  enthusiastic  friends  even,  though  pro- 
bably not  farmers  or  gardeners,  and  these  declare  that 
the  damage  done  is  slight  compared  with  the  service 
rendered.  The  soil  is  greatly  benefited,  say  they,  by 
being  upturned  and  lightened  ;  and  they  claim  that  the 
mole  takes  high  rank  among  nature's  field-labourers, 
and  should  be  honoured  accordingly,  not  only  for  his 
work  as  ploughman,  but  also  for  his  extraordinarily 
large  and  voracious  appetite  for  smaller  animals  of  all 
sorts,  which  do  far  more  injury  to  the  crops  than 
himself. 

It  is,  however,  too  much  to  expect  that  any  gardener 
of  tidy  mind  should  look  favourably  upon  an  animal 
which  throws  up  earthworks  in  the  middle  of  his  neat 
paths  and  borders.  The  mole  has  occasionally  done 
even  worse  damage  than  this  by  burrowing  through 
dams  and  dikes,  thereby  causing  inundations,  which, 
though  they  have  their  use  in  fertilizing  the  soil,  are 
not  generally  desirable  where  man  has  taken  over 
nature's  fields,  and  would  prefer  to  cultivate  them  in 
his  own  way. 


68  Field- Labourers 

Putting  aside  for  the  present  the  mole's  services  as  a 
devourer  of  injurious  insects,  which  are  certainly  great, 
we  may  perhaps  admit  that  we  do  not  now  need  him  as 
ploughman,  as  we  have  our  own  ways  of  doing  his 
work.  But  it  would  be  very  rash  to  say  that  we  could 
dispense  with  him  altogether;  and  even  if  we  could 
now,  this  need  not  make  us  overlook  the  share  which  he 
has  had  in  the  past,  and  in  unoccupied  lands  still  has, 
in  preparing  the  soil  for  our  use. 

Wherever  a  mole  lives  the  organic  matter  in  the  soil 
must  be  continually  receiving  increase,  for  it  lives 
almost  entirely  on  animal  food — such  as  worms,  grubs, 
insects,  as  well  as  mice,  dead  birds,  lizards,  frogs ;  and 
as  it  is  extraordinarily  voracious,  large  numbers  of  these 
must  be  consumed,  their  remains,  digested  or  not, 
being  left  in  the  earth.  Large  quantities  of  vegetable 
matter  are  also  carried  into  its  nest  by  every  mole 
every  year,  and  there  they  are,  of  course,  left  to  decay. 
When,  therefore,  one  thinks  of  the  thousands  of  moles 
still  existing,  and  the  many  more  thousands  and  mil- 
lions of  past  countless  generations,  every  one  of  which 
lives,  or  lived,  the  same  sort  of  life,  always  burrowing, 
always  feeding,  and  always  making  nests  year  by  year, 
it  is  evident  that  their  effect  upon  the  soil — in  places 
where  they  are,  or  have  been,  plentiful — can  certainly 
not  be  small. 

Some  might  like  to  be  rid  of  them  now.  though  pro- 
bably, if  they  had  their  will,  they  would  find  cause  to 
regret  it;  but  in  unoccupied  land  the  mole  has  cer- 
tainly done  much  service. 

And  now  we  turn  to  another  very  different  set  of 
workers,  most  unlikely  ones  we  should  say  at  first 
sight,  who  are  helping  to  improve  and  prepare  some  of 


Field-Labourer^  69 

the  limy  mud-flats  of  the  East  Indian  Archipelago. 
At  present,  we  believe,  their  work  has  been  watched 
only  on  the  Keeling  or  Coroz  Islands  ;  but  what  crabs 
are  doing  now  crabs  may  have  done,  and  have  most 
probably  done,  in  the  past,  so  that  some  part  at  least 
of  the  present  fertility  of  other  mud-flats,  perhaps  of 
coral  islands,  may  be  owing  to  them. 

But  what,  it  may  be  asked,  can  crabs  do  ?  They 
burrow,  for  one  thing ;  and  they  make  their  homes  so 
close  together  that  as  many  as  a  hundred  and  twenty 
of  these  narrow,  corkscrew  holes  have  been  counted  in 
a  space  only  two  feet  square,  so  that  the  ground  is  very 
thoroughly  perforated  indeed.  And  they  not  only 
burrow,  but  are  incessantly  busy  carrying  down  twigs, 
bits  of  seaweed,  scraps  of  coco-nut  shell,  seeds,  and  so 
forth,  with  the  object  of  making  themselves  comfort- 
able, it  is  to  be  supposed,  and  yet  it  almost  seems  as  if 
they  laboured,  some  of  them,  in  this  industrious  way 
simply  and  solely  for  the  sake  of  improving  the  soil. 

One  of  these  crabs  works  so  near  the  water  that  its 
burrows  are  covered  at  high  tide ;  another  works  a 
little  further  in,  and  a  third  further  still,  where  the  mud 
is  dry ;  but  what  is  curious  about  this  last  is  that  as 
soon  as  the  white,  chalky  mud  has  been  turned  into 
dark  vegetable  soil,  which  it  is  by  the  decay  of  the 
various  things  dragged  into  it — at  once  the  crab  goes 
off  to  another  fresh  spot,  and  begins  all  its  work  over 
again.  Perhaps  it  does  not  like  decayed  vegetable 
matter ;  but  the  result  is  that  it  is  always  at  work,  and 
must  get  through  a  good  deal  of  digging  in  the  course 
of  its  life. 

Further  inland  still,  the  soil  is  dry  and  turned  up  to 
the  sun  and  rain  by  the  '  great  coco-nut  crab,'  one  of 


70  Field-Labourers 

the  largest  that  live  on  the  shore,  whose  deep  tunnels 
are  larger  than  rabbit-burrows,  and  are  lined  with 
coco-nut  fibre. 

Beetles,  again,  are  most  useful  workers,  almost  all 
the  world  over,  and  on  some  of  the  wild  hill  slopes  of 
Ireland  all  the  patches  of  good  grass  are  said  to  be 
their  work.  Cows  are  kept  on  these  wastes,  and  are 
attended  by  numbers  of  large  beetles.  Three  or  four 
of  these  together  set  to  work  at  a  patch  of  cow-dung, 
burrowing  into  the  soil  beneath,  and  bringing  up  little 
heaps  of  clay  until  they  have  covered  it  three  or  four 
inches  deep.  Their  object,  no  doubt,  is  to  make  a 
suitable  place  in  which  to  lay  their  eggs,  for  the  grubs 
when  hatched  live  upon  this  food ;  but  they  at  the 
same  time  provide  a  suitable  bed  for  grass-seeds,  which 
is  quickly  taken  possession  of. 

The  Dumble  Dor  beetle,  or  Flying  Watchman,  the 
slow,  hump-backed,  bluish-black  creature,  which  is 
often  found  lying  on  its  back,  goes  to  work  in  a 
different  way,  and  in  spite  of  its  slow  movements  gets 
through  what  is  really  an  amazing  amount  of  work  for 
its  size.  We  all  know  it  probably,  though  we  may  not 
all  have  watched  its  operations.  It,  too,  is  an  attendant 
upon  cattle,  and  works  so  expeditiously  and  in  such 
large  numbers  as  to  clean  a  meadow  tenanted  by  cows 
in  three  or  four  days.  Instead  of  bringing  up  earth  to 
cover  the  droppings,  it  removes  them  altogether,  pellet 
by  pellet.  It  digs  its  way  down  between  the  grass- 
roots, carrying  with  it  as  much  as  it  can  to  a  hole  a 
foot  deep,  where  it  lays  one  egg ;  after  which  it  crawls 
up  again  for  more,  over  and  over  again,  making  many 
journeys.  As  many  as  forty  or  fifty  burrows  have  been 
counted  in  one  square  foot. 


Fie  Id- Labourers  *]  f 

In  tropical  countries,  where  animal  life  is  abundant, 
dung-beetles  of  many  species  are  especially  plentiful. 
The  great  Scarabseus  of  Egypt,  which  is  common 
throughout  Africa,  as  well  as  in  the  south  of  Europe, 
may  be  looked  upon  as  the  head  of  the  family,  some  of 
the  members  of  which  are  of  very  large  size.  Some  of 
the  family,  like  the  Carrion-eaters,  bury  the  dead 
bodies  of  small  animals,  which,  though  small,  are  many 
times  larger  than  themselves. 

Burying  beetles,  of  one  species  or  other,  are  every- 
where plentiful,  so  plentiful  indeed  that  we  very  seldom 
meet  with  the  dead  bodies  of  bird,  mouse,  or  mole,  or 
any  other  animal,  in  our  walks  in  field  or  wood.  All 
have  been  cleared  away  and  buried  several  inches, 
sometimes  nearly  a  foot,  underground,  where  they 
benefit  the  soil,  besides  providing  food  for  the  beetle's 
family — this  latter  being  of  course  the  only  object  which 
the  beetle  has  in  view.  They  work  sometimes  singly, 
sometimes  in  company,  scraping  the  earth  away  from 
beneath  the  carcase  with  their  forelegs,  and  then  care- 
fully covering  it  up  ;  after  which  they  burrow  down  and 
lay  their  eggs.  One  beetle  alone  has  been  known  to 
bury  a  mole  forty  times  its  own  weight ;  while  four 
together  have  been  seen  burying  a  crow;  and  if  we 
consider  for  a  moment  what  a  task  it  would  be  for  a 
man,  alone  and  unaided,  to  bury  an  animal  weighing 
forty  times  as  much  as  himself — say  four  hundred 
stone — we  may  gain  some  idea  of  the  vast  amount  of 
work  performed  by  these  insects.  Four  beetles  which 
were  kept  and  watched  for  fifty  days,  buried  in  that 
time  four  frogs,  three  small  birds,  two  fish,  one  mole, 
two  grasshoppers,  the  entrails  of  a  fish  and  two  pieces 
of  ox  liver.  But  even  rabbits  are  not  too  large  for 


72  Field-Labourers 

them ;  and  one  foreign  species  will  bury  a  snake  in  a 
few  hours. 

Burying  beetles  of  the  many  carrion-feeding  species 
abound  especially  in  temperate  climates,  for  there  it  is 
that  there  is  most  work  for  them  to  do,  since  there 
dead  bodies  decay  but  slowly.  In  those  parts  of  the 
tropics  where  great  heat  is  combined  with  extreme 
dryness — as,  for  instance,  on  the  Pampas  of  South 
America  or  in  the  African  deserts — a  body  is  dried  up 
so  quickly  that  it  can  hardly  be  said  to  decay  at  all. 
A  dead  horse  can  even  be  used  as  fuel,  and  there  the 
carrion-feeders  are  comparatively  few.  They  are  little 
needed  as  scavengers,  and,  unless  covered  up  imme- 
diately, the  dead  body  of  any  small  animal  such  as 
they  could  bury  would  supply  little  food  for  their 
grubs. 


VII. 

FIELD-LABOURERS — Continue^. 

'  THE  plough  is  one  of  the  most  ancient  and  most 
valuable  of  man's  inventions;  but  long  before  he 
existed  the  land  was,  in  fact,  regularly  ploughed,  and 
still  continues  to  be  thus  ploughed,  by  earthworms.' 

Earthworms  are  continually  busy  about  this  work 
over  pretty  nearly  the  whole  world,  'reversing  the 
earth's  crust,  turning  it  over  and  over,  from  year  to 
year,'  as  the  ploughman  does,  '  only  much  more 
slowly,  and  much  more  thoroughly,  spadeful  by  spade- 
ful, foot  by  foot,  and  even  grain  by  grain.'  And  the 
earthworm's  work  has  another  great  advantage  over 
that  of  the  ploughman.  It  is  not  only  more  thorough, 
but  it  can  be,  and  is,  carried  on  even  while  the  crops 
are  growing,  and  that  without  any  material  injury  to 
them. 

We  have  learnt  much  about  the  earthworm  of  late 
years,  thanks  to  Mr.  Darwin ;  but  long  before  '  Vege- 
table Mould  and  Earthworms'  was  written — more 
than  a  hundred  years  ago,  in  fact — Gilbert  White,  the 
naturalist  of  Selborne,  had  a  very  good  idea  of  the 
worm's  importance  as  one  of  nature's  field  labourers. 
'A  good  monography  of  worms,'  he  wrote,  'would 


74  Field- Labourers 

afford  much  entertainment  and  information  at  the 
same  time,  and  would  open  a  large  and  new  field  in 
natural  history/  '  Vegetation  would  proceed  but  lamely 
without  it,  so  great  are  its  services  in  boring,  per- 
forating, and  loosening  the  soil,  and  rendering  it 
pervious  to  rains  and  the  fibres  of  plants,  by  drawing 
straws  and  stalks  of  leaves  and  twigs  into  it,  and,  most 
of  all,  by  throwing  up  such  infinite  numbers  of  lumps 
of  earth,  which  is  a  fine  manure  for  grain  and  grass.' 

Gardeners  and  farmers  hated  the  worm  in  his  day, 
as  the  former  at  least  do  still ;  but  he  remarks  that 
they  would  find  '  the  earth  without  worms  would  soon 
become  cold,  hard-bound,  and  void  of  fermentation, 
and  consequently  sterile.' 

The  earthworm  is  an  animal  possessed  apparently 
of  more  than  the  traditional  nine  lives,  and  endowed 
with  a  wonderful  power  of  adapting  itself  to  the  most 
diverse  and  most  adverse  circumstances.  Bodily  injury 
affects  it  but  little,  so  far  as  life  is  concerned.  One 
worm  is  said  to  have  been  beheaded  eight  times  in 
succession,  and  to  have  perseveringly  grown  a  new 
head  each  time ;  another  was  cut  into  fourteen  pieces, 
thirteen  of  which  became  perfect  worms,  while  only 
one  died. 

Earthworms  closely  similar  in  appearance  to  those 
which  we  know  in  England  are  found  in  soils  of  the 
most  various  kinds  and  in  almost  all  parts  of  the  world. 
The  English  species  is  extremely  plentiful  on  commons 
and  chalk  downs,  where  the  soil  is  poor  and  the  grass 
short  and  thin,  and  it  is  almost  equally  abundant  in 
some  of  the  London  parks,  where  the  soil  is  rich. 
But  their  numbers  may  vary  in  different  parts  even 
of  the  same  field,  showing  that  they  have  their  pre- 


Field- Labourers  75 

ferences,  though  it  may  not  always  be  easy  to  discern 
the  reason  for  them.  Moisture,  however,  they  cannot 
do  without,  and  hence,  while  they  avoid  dry  sand  and 
heaths,  they  frequent  paved  yards  near  houses  in  large 
numbers. 

On  the  mountains  of  North  Wales  and  on  the  Alps 
they  are  rare,  owing  perhaps  to  the  lack  of  sufficient 
depth  in  which  to  make  their  winter  burrows;  but 
they  are  found  in  Scotland  on  hills  1,500  feet  above 
the  sea  ;  near  Turin,  at  a  height  of  2,000  or  3,000  feet ; 
on  the  Nilgiri  Mountains  of  South  India,  and  on  the 
Himalayas.  They  have,  indeed,  an  enormous  range, 
occurring  in  the  most  isolated  islands,  abounding  in 
Iceland,  and  found  in  the  West  Indies,  St.  Helena, 
Madagascar,  New  Caledonia,  Tahiti,  Kerguelen's  Land, 
and  the  Falkland  Islands,  though  how  they  reached 
these  is  at  present  a  mystery,  since  sea-water  is  abso- 
lutely fatal  to  them.  In  the  United  States  they  are 
plentiful ;  in  Venezuela,  common  in  gardens  and  fields ; 
in  South  Brazil  the  soil,  to  the  depth  of  a  quarter  of  a 
yard  or  more,  looks  in  most  parts  of  the  forest  and 
pasture  land  as  if  it  had  repeatedly  passed  through 
their  bodies.  Even  in  the  dry  soil  of  New  South  Wales 
their  castings  abound,  and  in  the  hot,  moist  jungles  of 
Bengal  they  occur  almost  everywhere. 

Strange  to  say,  they  seem  to  be  either  absent  or 
uncommon  in  the  Canadian  prairies — that  is,  they 
never  seem  to  have  come  in  the  way  of  the  surveyors ; 
but,  after  all,  this  does  not  prove  much. 

Almost  the  whole  surface  of  every  moderately  damp 
country  is  covered  with  a  layer  of  fine,  dark,  vegetable 
mould ;  it  is  only  a  few  inches  thick  at  most,  from  four 


j6  Field- Labourers 

or  five  to  perhaps  twelve  inches,  but  no  matter  what 
the  nature  of  the  soil  beneath,  there  it  is.  One  may 
see  it  in  any  railway  cutting,  or  on  the  top  of  any  bank, 
be  it  chalk  or  be  it  sand  ;  and  this  black  earth,  or 
humus,  is,  to  a  very  large  extent,  the  work  of  worms. 

In  a  very  loose  soil  worms  can  move  easily,  but, 
generally  speaking,  as  their  bodies  are  soft,  and  cannot 
pierce  through  anything  at  all  hard  or  close,  and,  as 
they  have  nothing  but  their  mouths  to  work  with, 
they  are  obliged  to  eat  their  way  through  the  ground. 
No  doubt  they  are  fed,  to  some  extent,  by  the  animal 
or  vegetable  matter  contained  in  the  soil,  but  their 
primary  object  in  swallowing  it  does  not  seem  to  be 
food ;  to  swallow  it  is  the  only  way  they  have  of 
getting  rid  of  it,  and  their  real  object  is  to  make  a  tube 
or  burrow  in  which  to  live. 

Where  other  food  is  scarce,  or  absent,  they  must, 
of  course,  live  on  what  they  can  get  from  the  soil,  and, 
in  purely  mineral  soils,  they  are  rare  accordingly,  as 
they  could  not  find  sufficient  nourishment  in  it  in  case 
of  necessity. 

The  effect  produced  upon  the  soil  by  its  passage 
through  their  bodies  is  very  marked:  it  is  not  only 
rendered  extremely  fine,  but  its  colour  is  gradually 
altered,  becoming  darker  and  darker,  until,  after  re- 
peated swallowing,  it  is  turned  almost  black.  The 
layer  of  dark  mould  which  covers  our  fields  is  dark  just 
because  it  is  composed  of  the  castings  of  worms, 
castings  which  have  passed  through  their  bodies  over 
and  over  again,  times  innumerable. 

The  worm  has  no  teeth,  and  its  mouth  is  a  mere 
opening,  but  it  has  the  power  of  flattening  its  head  and 
extending  it  on  each  side  of  this  opening  so  as  to  form 


Field- Labourers  77 

two  lips,  with  which  it  is  able  to  grasp  leaves  and 
other  things  firmly  enough  to  drag  them  into  its 
burrow.  Sometimes,  however,  it  seems  to  vary  its 
manner  of  proceeding,  and,  instead  of  grasping  the 
object  it  wishes  to  move,  it  presses  its  mouth  upon  it 
until  it  adheres  firmly  by  mere  suction. 

Worms  are  omnivorous :  they  will  eat  anything 
eatable,  and  will  feed  daintily  upon  half-decayed 
flowers  and  almost  any  kind  of  vegetable  matter,  or 
coarsely  upon  their  own  dead  comrades,  or  meat  when 
put  in  their  way.  But  their  chief  food  consists  of  half- 
decayed  leaves,  enormous  quantities  of  which  are 
pulled  into  their  burrows,  torn  into  small  shreds,  and 
then  swallowed  and  digested ;  and  it  is  this  vegetable 
matter  which  changes  the  colour  of  the  earth  which 
the  worms  swallow  with  it,  and  converts  it  into  '  mould ' 
— vegetable  mould. 

Two  worms  kept  in  a  large  pot  of  sand,  well 
moistened,  of  course,  but  consisting  only  of  mineral 
matter,  converted  the  top  layer  into  vegetable  mould 
four  inches  deep,  simply  by  the  help  of  the  leaves 
strewed  on  the  surface. 

In  woods  the  fallen  leaves  are  being  constantly 
covered  with  worm  castings,  and  thus  converted  into 
rich  soil ;  and  in  Sumatra  the  ground  in  the  forests  is 
almost  as  rough  as  a  field  which  has  been  literally 
ploughed,  so  thickly  is  it  covered  with  large  worm 
heaps  eight  inches  high,  often  thrown  up  in  a  single 
night.  There  may  be  as  many  as  ten  or  twelve  of 
these  in  a  square  yard,  and  the  creatures  seem  to  be 
incessantly  at  work  bringing  up  soil  and  burying  leaves, 
twigs,  etc. 

As  to  the  actual  amount  of  soil  swallowed  by  worms, 


£8  Field- Labourers 

it  varies,  of  course,  according  to  their  size,  in  which 
they  differ  very  greatly.  There  is  a  worm  in  Ceylon 
about  two  feet  long ;  in  the  Nilgiri  Hills,  already 
mentioned,  they  are  twelve  or  fifteen  inches  long  and 
as  thick  as  a  man's  little  finger ;  while  on  the  Amazon 
there  are  some  as  much  as  two  feet  and  a  half  long 
and  thick  in  proportion,  and  able  therefore  to  do  much 
work. 

Seeing  only  the  little  dark  heaps  of  soil  thrown  up 
by  worms  on  grass-plots  and  gravel-paths,  heaps  which 
are  soon  washed  down  again  by  rain,  one  has  some 
difficulty  in  realizing  the  vast  amount  brought  up  in 
the  course  of  a  year.  But  Mr.  Darwin  reckoned  that 
near  Nice  this  amounts  to  from  about  fourteen  to 
eighteen  tons  to  the  acre ;  this  is  supposing  them  to  be 
as  numerous  and  active  over  the  whole  of  a  field  as 
they  were  in  the  one  square  yard  chosen  for  observa- 
tion ;  but  it  is  also  supposing  them  to  work  for  only 
six  months  of  the  year,  which  he  considered  a  low 
estimate.  The  largest  amount  was  brought  up  on  very 
poor  pasture,  where  leaves  were  probably  scarce,  and 
the  worms  had  to  swallow  much  earth  in  order  to 
obtain  sufficient  food. 

On  the  whole  it  seems  probable  that  they  bring  up 
more  than  ten  tons  of  soil  to  the  acre  in  many  parts  of 
England  year  by  year,  and  that  the  entire  mass  of 
mould — the  dark  surface-soil  of  every  field — passes 
through  their  bodies  in  the  course  of  a  few  years,  and 
is  by  these  means  sifted  and  rendered  extremely  fine, 
besides  being  thoroughly  impregnated  with  vegetable 
and  animal  matter.  Moreover,  bones,  twigs,  leaves, 
shells,  are  constantly  being  covered  with  castings,  and 
these  further  help  to  enrich  the  soil  by  their  decay; 


Field-Labourers  79 

whereas,  left  upon  the  surface,  they  would  benefit  it 
but  little.  Large  earthworms  sometimes  bring  up 
soil  from  a  great  depth :  in  sandy  soils,  for  instance, 
their  tubes  go  down  from  three  or  four  to  six  feet,  and 
are  then  continued  horizontally  ;  and  the  whole 
contents  of  these  tubes  must,  of  course,  be  brought  to 
the  surface. 

Estimates  differ  so  much  that  it  seems  hopeless  at 
present  to  try  and  calculate  their  numbers.  But  this 
one  thing  we  know,  there  are  many  thousands  in  every 
acre  of  moderately  damp  land,  and,  grain  by  grain,  the 
whole  surface  is  literally  'loughed  and  saturated  with 
fertilizing  juices. 

So  far  from  being  over-rated,  as  some  have  thought, 
the  earthworm  is  now  proved  to  be  an  even  more 
valuable  field-labourer  than  was  supposed,  and  it  is 
said  that,  in  estimating  the  value  of  land  for  farming 
purposes,  no  satisfactory  conclusion  can  be  arrived  at 
unless  the  number  of  worm-holes  be  taken  into  the 
account. 

Besides  grinding  up  the  soil  in  the  process  of 
digestion  to  a  state  of  extreme  fineness,  besides  adding 
to  it  vegetable  matter  and  darkening  its  colour,  worms 
are  most  useful  in  another  way  :  they  prepare  channels 
through  which  the  roots  of  plants  are  able  to  spread 
with  ease.  Plants  evidently  prefer,  when  they  can,  to 
take  advantage  of  ready-made  passages,  and  worm 
burrows  which  have  been  in  existence  some  little  time 
are  usually  found  lined  to  the  very  end  with  fine  roots 
and  rootlets,  the  latter  covered  with  fine  hairs,  through 
all  of  which  the  plant  absorbs  food. 

Roots  of  red  clover  have  been  found  running  down 
six  feet,  or  more,  into  the  ground  by  means  of  these 


So  Field- Labourers 

holes,  and  the  plant  of  course  gains  by  this.  The 
longer  the  root,  the  larger  the  surface  with  which  it  is 
brought  in  contact,  and  the  larger  the  supply  of  food 
which  it  can  extract;  and  it  obtains  this  food  more 
quickly  where  it  can  run  through  a  tube  than  where  it 
has  to  force  its  way  through  close  soil,  and  con- 
sequently the  plant  grows  more  rapidly. 

Much  of  this  will  be  more  readily  understood  when 
we  come  to  speak  of  how  plants  feed  and  grow ;  but 
we  may  mention  here  that  plants  which  are  able  to 
send  down  roots  to  any  considerable  depth  have  the 
advantage  of  reaching  soil  which  is  quite  fresh  and 
unexhausted ;  they  have  also  plenty  of  room  in  which 
to  develop  their  roots,  and,  more  important  still,  their 
roots  are  kept  warm  and  well  supplied  with  moisture 
at  all  times,  even  when  the  surface  of  the  ground  is 
frozen  hard.  Dig  through  the  frozen  surface,  and  you 
will  always  find  moist  earth  beneath ;  so  also  even  in 
drought,  there  will  be  more  moisture  below  than  on 
the  surface ;  and  this  moisture  plants  are  enabled  to 
reach  by  means  of  the  worm -tubes,  instead  of  spread- 
ing their  roots  only,  or  chiefly,  through  the  surface- 
soil  as  they  might  otherwise  do. 

However,  as  we  have  observed  already,  man  may 
tame  a  lion,  but  he  cannot  control  a  single  worm — 
cannot  make  his  wishes  understood  or  respected  by 
one  of  these  insignificant  creeping  things  ;  and  so,  as 
the  worm's  proceedings  are  at  times  exceedingly  irre- 
gular, he  blames  the  worm,  and  sometimes  goes  so  far 
as  to  deny  that  it  does  any  good  at  all 

Their  way  of  top-dressing  lawns  and  paths  does  not 
improve  the  appearance  of  either,  we  must  admit ;  top- 
dressing  may  be  all  very  well  in  a  meadow,  or  in  the 


Field-Labourers  8 1 

rice-fields  of  Bengal,  which  are  very  soon  studded  with 
worm-heaps  after  they  have  been  flooded,  but  in  a 
garden  we  are  inclined  to  think  it  out  of  place.  And 
it  is  true  that,  in  the  Botanic  Gardens  of  Calcutta,  the 
lawns  are  covered  in  a  single  night  or  two,  if  they  are 
left  unrolled,  with  tower-like  castings,  which  weigh 
some  ounce  and  a  quarter  each,  and  are  anything  but 
sightly. 

Sometimes,  too,  the  earthworm  may  disturb  seed- 
lings by  burrowing,  but  it  does  not  eat  them.  Neither 
does  it  touch  living  roots,  as  it  has  been  suspected  of 
doing,  at  least  when  these  are  growing  in  the  open 
ground  ;  though  what  it  may  do  when  confined  in  a 
pot,  and  pressed  by  hunger,  is  perhaps  another  matter. 

In  spite  of  some  drawbacks,  however,  it  would  be 
not  merely  hard  but  absolutely  impossible  for  man  to 
contrive  any  substitute  for  these  natural  ploughmen  if 
he  could  succeed  in  banishing  them. 

But  people  are  never  all  satisfied ;  and  among  the 
malcontents  are  some  who  find  fault  with  the  worm, 
not  for  doing  too  much,  but  for  doing  too  little !  It 
works,  say  they,  only  for  a  few  months  of  the  year, 
and  therefore  does  not  deserve  so  much  credit  and 
gratitude  after  all. 

The  poor  worm  cannot  work  in  dry  soil.  Indeed, 
moisture  seems  to  be  the  one  thing  essential  to  it ;  for 
though  it  can  stand  much  bodily  ill-usage,  it  is  actually 
killed  by  exposure  to  the  dry  air  of  a  room  for  even  a 
single  night.  In  hot  countries,  such  as  Bengal,  there- 
fore, it  can  only  work  during  the  cool  season,  about; 
two  months,  after  the  rains ;  and  even  in  the  moist 
climate  of  England  it  cannot  work  near  the  surface 
during  the  dry  weather  of  summer,  any  more  than 

6 


82  Field-Labourers 

in  hard  frost.  Gilbert  White  remarked  that  worms 
worked  most  in  spring ;  but  he  added  that  they  were 
by  no  means  torpid  during  the  dead  months,  and  were 
in  fact  out,  even  in  winter,  on  every  mild  night. 

There  is,  however,  another  and  much  smaller  animal, 
which,  as  some  people  think,  has  done  much  work 
hitherto  attributed  to  the  overpraised  worm.  Ants 
have  not  generally  had  the  reputation  of  being  useful 
to  the  agriculturist,  however  clever  some  of  them  may 
be  as  agriculturists  on  their  own  account ;  but  in 
Ireland,  according  to  at  least  one  observer,  they  do 
appear  to  have  been  most  useful ;  and  if  in  Ireland, 
then  why  not  elsewhere  ? 

These  Irish  hill-building  ants  love  what  the  worm 
cannot  bear,  a  dry,  sandy,  or  peaty  soil ;  and  they  are 
busy  at  work  from  early  spring  to  late  autumn,  all 
through  the  hot  weather,  when  the  worm  is  compara- 
tively idle.  Yet  even  so,  they  do  not  work  for  more 
than  about  five  months  of  the  year ;  whereas  the  worm 
works  on  an  average  at  least  six,  and  in  mild,  damp 
Winters  often  much  more. 

However,  whatever  their  respective  merits,  the  ants 
work  where  and  when  the  worms  cannot  do  so,  and 
are  most  useful  where  there  are  crags,  or  large  stones, 
with  patches  of  sandy  peat ;  for  the  hill-building  ants 
always  choose  rock  to  build  upon,  and  gradually  cover 
the  surface  with  soil.  These  patches  are  at  once  taken 
possession  of  by  grass  and  other  seeds,  and  so  the  soil 
is  kept  in  place.  During  the  winter  there  may  be  a 
little  loss  by  wind  and  rain,  but  the  greater  part  is 
held  together  by  the  roots,  and  a  patch  of  permanent 
vegetation  is  formed  where  previously  there  was  only 
bare  stone. 


Field- Labourers  83 

A  single  colony  of  ants  seldom  covers  less  than  two 
Square  feet,  and  sometimes  more  than  three;  and 
as  they  generally  choose  a  fresh  place  every  year, 
they  really  do  a  great  deal  towards  clothing  bare 
places. 

The  ants  which  work  on  the  sandy  moors  seem  to 
keep  to  the  same  spot  year  after  year,  but  their  hillocks 
are  much  taller,  sometimes  as  much  as  four  feet  high 
and  a  yard  across  at  the  base,  all  composed  of  soil 
brought  up  from  below  mixed  with  refuse  vegetable 
matter,  and  in  this  way  much  of  the  unprofitable  peat 
is  converted  into  good  soil. 

In  some  parts  of  Ireland  the  work  done  by  ants  is, 
if  not  larger,  at  least  much  more  noticeable  than  that 
done  by  worms,  and  it  is  believed  that  the  space 
covered  by  the  work  of  the  two  is  about  equal. 

But  in  the  tropics  worms  are,  of  course,  quite  power- 
less during  the  greater  part  of  the  year,  the  soil  being 
either  baked  to  a  brick  or  dried  to  dust.  In  the  burn- 
ing deserts  of  Nubia  a  worm  was  never  seen  or  even 
heard  of,  and  even  in  a  tropical  forest  during  nine 
months  of  the  year  the  soil  is  so  hard  as  to  be  quite 
unmanageable  by  its  jaws. 

In  the  sub-tropical  parts  of  South  America  and  India, 
worms  swarm  out  in  endless  numbers  when  the  rain 
comes,  but  in  the  tropics  proper,  except  in  the  moister 
regions,  they  are  on  the  whole  few.  Not  one  was  seen 
by  Professor  Drummond  in  Central  Africa,  even  during 
rain,  and  he  suggests  that  their  place  is  taken  in  these 
parts  by  the  termite,  commonly,  though  erroneously, 
called  the  white  ant. 

The  white  ant  lives  underground,  and  being  quite 
defenceless,  it  has  such  a  dread  of  exposure  that  when 


84  Field- Labourers 

obliged  to  come  out  for  food  it  brings  some  of  the  earth 
with  it,  and  builds  a  tunnel  within  which  it  always 
remains. 

The  food  of  the  termite  is  dead  wood,  and,  not 
content  with  what  it  finds  on  the  ground,  it  climbs  the 
trees  in  search  of  it,  toilsomely  carrying  earth  for  its 
tunnels  wherever  it  goes.  There  may  be  perhaps  a  few 
feet  of  dead  wood  at  the  end  of  a  long  branch  some 
thirty  feet  from  the  ground,  and  the  whole  distance 
must  be  covered  in  if  the  termite  is  to  reach  it.  But 
as  it  does  not  know  exactly  where  the  food  desired  is 
to  be  found,  it  more  often  than  not  covers  the  whole 
tree  with  tunnels  and  galleries  made  on  speculation. 

The  extent  to  which  this  tunnelling  is  carried,  and  the 
amount  of  earth  brought  up,  are  something  incredible. 
In  some  districts  of  tropical  Africa  there  are  millions 
of  trees  covered  with  tubes,  every  one  of  which  must 
be  plastered  over  with  many  pounds  of  soil.  The 
tunnels  generally  are  about  the  size  of  a  small  gas-pipe, 
some  occasionally  larger,  and  here  and  there  are  large 
chambers  covering  nearly  the  whole  trunk  for  some 
feet.  Every  branch,  every  twig  has  a  tunnel,  and  as 
for  the  dead  wood  which  falls  to  the  ground,  none  is 
ever  to  be  seen,  as  it  is  at  once  encased  in  soil.  At 
first  sight  the  traveller  may  think  he  has  found  a  faggot, 
but  on  closer  inspection  it  proves  to  be  nothing  but  a 
cast  in  mud,  a  very  perfect  cast,  with  all,  even  the 
minutest,  knots  reproduced. 

But  of  trunks,  branches,  boughs,  or  even  twigs  lying 
about  on  the  ground,  there  is  nothing  to  be  seen.  All 
are  eaten  up. 

The  outside  texture  of  the  termite  galleries  is  like 
that  of  coarse  sand-paper;  but  being  intended  for 


Field- Labourers  85 

temporary  purposes,  only  they  crumble  into  dust  after 
a  little  exposure.  But  the  dust,  brought  up  from  the 
sub-soil  in  the  first  instance  and  now  returned  to  earth 
again  or  scattered  abroad  by  the  wind,  has  been  altered 
in  character ;  it  has  been  powdered  for  one  thing,  and 
it  has  been  to  some  extent  mixed  with  animal  juices  for 
another,  since  the  only  '  mortar '  at  the  termite's 
command  is  its  own  saliva,  by  means  of  which  it  makes 
the  grains  adhere  together.  So  far,  then,  the  soil  which 
the  termite  has  brought  up  from  below  is  richer  than 
before  ;  but  the  chief  point  gained  seems  to  be  that  the 
soil  is  being  constantly  turned  over  and  over. 

Some  districts  are  more  especially  favourable  to  the 
termite  than  others,  and  in  one  of  these  there  are  miles 
of  trees  all  covered  with  its  earthworks.  '  The  soil  of 
the  tropics  is  therefore  in  a  state  of  perpetual  motion. 
Instead  of  the  upper  crust  being  converted  into  a  paste 
by  the  autumn  rain  and  then  baked  to  adamant,  the 
under  soil  being  hermetically  sealed  up  from  light  and 
air,  there  is  a  slow  constant  transference,  grain  by 
grain.' 

But  the  tunnels  do  not  represent  nearly  all  the 
termite's  work,  though  they  are  much.  Besides  these, 
there  are  the  nests,  mounds  of  earth  of  huge  size, 
which  are  a  common  feature  of  the  African  landscape, 
and  can  be  seen  for  miles.  In  India  they  are  seldom 
more  than  a  couple  of  feet  or  so  in  height,  but  in 
Central  Africa  they  are  from  ten  to  seventeen  feet  high 
and  contain  many  tons  of  earth,  while  the  excavations 
beneath  are  many  feet  and  even  yards  deep. 

The  mounds  are  not  solid,  but  composed  of  many 
tunnels,  chambers,  and  galleries,  yet  they  are  so  strong 
that  they  will  bear  the  weight  of  a  man  on  horseback 


86  Field- Labourers 

The  exterior  is,  indeed,  brick-like  or  stone-like  in  its 
hardness,  but  with  all  its  strength  it  must  give  way  at 
last  beneath  the  fury  of  the  tropical  rains,  which 
continue  off  and  on  for  two  or  three  months  at  a  time, 
and  thus  the  soil  is  returned  to  the  earth  enriched  by 
its  admixture  with  animal  matter. 

Ants,  true  ants,  as  well  as  white  ants,  abound  every- 
where within  the  tropics,  but  they  also  do  a  large 
amount  of  work  outside,  though  their  numbers  gradually 
diminish  as  we  go  further  and  further  north  and 
south. 

There  are  '  ant-cities  '  in  Pennsylvania,  each  of  which 
contains  more  than  1,600  nests  of  various  size,  the 
largest  being  fifty-eight  feet  round  the  base  and  forty- 
two  inches  high,  with  galleries  some  sixty  feet  long 
leading  to  the  feeding  grounds. 

The  muscular  power  of  these  ants  is  truly  wonderful. 
The  loads  they  carry  are  twenty-five  times  their  own 
weight,  and  they  carry  them  what,  for  their  size,  is  an 
enormous  distance.  It  is  as  if  a  man  of  ordinary  size 
were  to  carry  a  weight  of  4,000  pounds  from  the  bottom 
of  a  coalpit  to  the  top  of  the  Great  Pyramid.  And  they 
have  not  merely  to  carry  these  loads,  but  first  to  prepare 
them. 

The  ant  begins  work  by  scratching  with  her  forelegs 
like  a  dog  ;  later  on  she  bites,  cuts,  or  twists  off  pellets 
of  earth,  during  which  process  she  often  works  like  a 
collier  on  her  back,  and  then  she  compresses  the 
particles  into  a  ball  and  carries  them  out.  The  only 
implements  she  has  for  her  work  are  her  mandibles, 
or  first  pair  of  jaws,  which  are  placed  outside  her 
mouth,  each  jaw  being  furnished  with  seven  teeth. 
These  powerful  jaws  serve  as  pick,  shovel,  crowbar, 


Field- L  abourers  8  7 

saw,  axe,  and  cart,  all  in  one,  and  as  the  little  creature 
grows  old  her  teeth  are  gradually  worn  down  by  the 
hard  work  they  have  done,  just  as  a  workman's  tools  are 
worn. 

The  number  of  these  ants  is  simply  enormous ;  and, 
besides  enriching  the  ground  by  the  quantity  of  leaves 
with  which  they  fill  their  storehouses,  they  also  per- 
forate it  to  a  considerable  depth.  Some  of  their  sub- 
terranean galleries  have  been  traced  down  fifteen  feet, 
and  found  to  be  still  descending.  Whatever  the  depth 
may  be,  from  it  they  bring  up  the  soil  with  which  they 
build  their  mounds  ;  and  in  Brazil  there  are  very  large 
deposits  of  earth  which  have  been  raised  to  the  surface 
entirely  by  the  ants. 

Thus  not  only  is  fresh  soil  continually  exposed  to  the 
action  of  air  and  rain,  but  ways  are  opened  by  which 
the  same  air  and  rain  may  penetrate  to  the  underlying 
rocks  and  carry  on  the  decaying  process,  as  described 
in  an  earlier  chapter.  Nor  must  it  be  forgotten  that 
wherever  there  is  decaying  vegetable  matter,  there 
carbon-dioxide  and  other  gases  are  formed,  which  are 
absorbed  by  the  rain  in  its  passage  through  the  earth, 
and  increase  in  a  very  high  degree  its  power  of  acting 
upon  the  rocks  beneath. 

The  ants'  store-rooms,  the  worms'  burrows  with 
their  quantity  of  decaying  leaves,  the  ground-squirrel's 
hoards,  and  the  beds  made  for  themselves  or  their 
young  by  mole,  marmot,  and  the  like,  all  increase  the 
organic  matter  and  the  supply  of  carbon-dioxide  in  the 
soil ;  while  their  various  burrows,  large  and  small, 
make  an  easier  passage  for  the  rain. 

We  cannot  attempt  to  give  more  than  a  sketch,  ancj 


88  Field- Labourers 

that  a  very  slight  one,  of  the  work  done  by  nature's 
various  field-labourers ;  but,  slight  as  it  is,  it  would  be 
incomplete  without  some  mention  of  the  very  curious 
animals  known  as  ant-eaters,  which  are  found  through- 
out the  tropics. 

These  creatures  have  very  long,  thin,  pliable  tongues, 
looking  like  red  earthworms,  and  as  if  they  were  en- 
dowed with  independent  life ;  and  when  they  can  get 
at  them  they  lick  up  the  ants  with  marvellous  rapidity. 

The  ants,  as  we  have  seen,  dwell,  many  of  them, 
within  walls  almost  as  hard  and  strong  as  if  built  of 
stone  or  brick,  capable,  one  would  think,  of  defying  the 
attack  of  almost  any  animal.  But  ant-eaters  are  armed 
with  tremendously  powerful  claws — so  powerful  that 
with  them  they  are  able  to  dig  and  tear  down  even 
these  strong  citadels;  and  this  done,  they  sweep  up 
the  terrified  inhabitants  by  thousands. 

Ant-eaters  of  the  Manis  family,  long-tailed  and  short- 
tailed,  which  are  found  in  Africa  and  Asia,  are  covered 
with  horny  plates,  sharp-edged  and  overlapping,  the 
points  turned  to  the  tail  and  raised,  so  that  they  have 
the  combined  advantages  of  scale-armour  and  the 
hedgehog's  bristles. 

The  Aard-Vark,  or  Earth-hog,  of  South  Africa,  is  a 
very  different-looking  animal,  covered  with  coarse, 
bristly  hair,  and  about  five  feet  long  with  its  tail— 
altogether  too  large,  one  would  have  fancied,  to  be 
satisfied  with  such  very  small  food  as  ants.  Its  fore- 
limbs  are  very  powerful,  and  armed  with  long,  hoof- 
like  claws,  with  which  it  digs  through  the  hardest 
mounds  and  burrows  in  the  hard -baked  earth  faster 
than  a  man  can  dig  with  a  spade. 

The  great  Ant-eater,  or  Ant-bear  of  tropical  South 


Field- Labourers  89 

America,  is  like  the  Aard-Vark,  but  larger,  and  is  so 
bold  that  it  will  sit  up  and  fight  even  a  '  tiger,'  or  more 
properly  jaguar,  with  the  very  long  curved  claws  of  its 
fore-feet.  Yet,  notwithstanding  its  size  and  strength, 
it  lives  chiefly  on  ants. 

By  these  and  other  ant-eaters  the  hills  and  mounds 
of  the  ants  are  demolished,  and  the  earth  which  they 
have  excavated  with  so  much  labour  is  returned  to  the 
soil.  And  it  is  returned  in  an  altered  state,  much  finer 
than  before,  and  enriched  to  some  extent  at  least  by 
what  has  been  added  to  it,  and  so  is  better  fitted  for 
the  support  of  plant-life. 


VIII. 

WATER 

THE  soil  may  have  been  ground  and  mixed,  perhaps 
transported  long  distances,  and  otherwise  prepared  by 
the  various  labourers  already  described ;  but  even  then 
no  crops,  whether  wild  or  cultivated,  can  thrive  in  it 
without  moisture.  In  perfectly  dry  soil  they  must 
starve  in  the  midst  of  plenty ;  for  they  can  no  more 
get  at  the  food  around  them,  however  abundant  it 
may  be,  without  water,  than  if  it  were  locked  up. 
To  them,  indeed,  under  such  circumstances,  it  is 
locked  up. 

Of  course,  we  all  know,  as  a  matter  of  fact,  that 
plants  fade  and  wither,  and  eventually  shrivel  and  die, 
if  they  be  kept  without  water.  We  may  know,  too, 
that  three-quarters  of  the  weight  of  most  plants,  and  a 
great  deal  more  of  many,  is  made  up  of  nothing  but 
water.  But  when  once  they  have  had  a  supply  of 
water,  why  should  they  need  more  ?  Cannot  they  keep 
it  ?  and  if  not,  how  do  they  lose  it  ?  Why  do  they 
need  constant  watering  ? 

A  potato  is  watery :  only  one-fourth  of  its  weight  is 
solid  matter  ;  the  rest  is  all  water.  An  artichoke  con- 
tains still  more  water,  and  still  less  solid  matter;  a 


Water  gi 

turnip  is  more  watery  still ;  and  a  pumpkin  contains 
only  five  and  a  half  per  cent,  of  solid  matter. 

And  yet,  when  we  have  stored  our  potatoes  and 
turnips,  or  our  pumpkins,  we  do  not  find  it  necessary 
to  water  them.  They  do  not  shrivel ;  they  keep  their 
moisture.  Why  does  not  a  plant  do  the  same  ? 

The  only  answer  to  this  question  is,  simply  because 
it  can't.  It  cannot  shut  the  many  mouths  by  which  it 
is  constantly  losing  moisture.  We  human  beings  can- 
not prevent  the  escape  of  water  through  the  pores  of 
our  skin,  or  in  the  breath  which  we  breathe ;  and  the 
plant  is  in  similar  case.  It  is  constantly  giving  off 
water,  and  if  the  loss  is  not  made  up  it  must  needs  be- 
come dry  and  shrivel. 

Almost  every  part  of  a  plant  which  is  exposed  to  the 
air,  and  not  covered  by  a  layer  of  cork  or  of  thickened 
skin,  is  constantly  losing  moisture  in  ordinary  air  ;  and 
unless  the  roots  can  suck  up  enough  to  make  the  loss 
good,  it  droops,  flags,  withers,  and  dies. 

The  potato  and  the  pumpkin  are  protected — the  one 
by  cork,  the  other  by  thick  skin — and  they  are  there- 
fore able  to  retain  their  moisture  for  a  considerable 
time.  In  a  similar  way,  the  stems  of  most  woody 
plants  and  trees  are  protected  by  layers  of  cork,  and 
often  of  fibrous  bark  as  well,  which  almost,  though  not 
altogether,  prevent  the  escape  of  water.  It  is  the 
young,  green  stems,  the  growing  parts,  and  the  leaves 
by  which  it  is  chiefly  allowed  to  go  off  into  the  air ; 
and  these  are  just  the  parts  which  especially  need  the 
mineral  food,  the  food  derived  from  the  soil,  which  the 
roots  are  constantly  preparing. 

How  are  the  roots  to  convey  this  food  to  the  growing 
parts  of  the  plant?  Of  course,  they  cannot  do  so; 


92  Water 

they  can  only  make  it  ready,  and  then  it  must  be 
pumped  up  to  where  it  is  wanted.  Accordingly,  as  the 
water  is  drawn  off,  so  to  say,  above,  the  sap  from  below 
— that  is,  water  containing  food  from  the  soil — rises  to 
supply  its  place. 

A  constant  current,  therefore,  rises  from  the  roots 
upwards ;  but  a  great  deal  of  this  would  be  lost  during 
its  passage  before  it  reached  the  young  shoots  but  for 
the  fact,  already  mentioned,  that  the  trunks  or  stems 
through  which  it  passes  are  protected  against  the  air, 
and  moisture  can  escape  but  very  slowly  through  bark 
or  cork,  though  it  does  still  escape  to  some  small 
extent. 

When  the  sap  reaches  the  green  parts  of  the  plant 
it  passes  off  into  the  air  as  invisible  vapour;  or, 
rather,  the  water  of  the  sap  passes  off  in  this  way, 
and  the  food  from  the  soil,  the  mineral  matter,  is 
left  behind.  But  even  from  the  green  stems  and  leaves 
the  water  is  not  allowed  to  escape  quite  unchecked, 
else  it  might  pass  off  too  fast — faster  than  it  could  be 
supplied. 

For  anything  moist,  whether  it  be  moist  earth  or 
wet  clothes,  dries  when  exposed  to  the  air.  The  air 
sucks  the  moisture  out  of  all,  and  the  drier  the  air, 
the  more  quickly  it  sucks.  Without  some  protection 
against  this  thirsty  air,  therefore,  leaves  and  green 
stems  would  also  be  sucked  dry,  like  anything  else, 
and  accordingly  their  outer  skin  is  more  or  less 
thickened ;  and  it  often  contains,  or  is  covered  by,  a 
waxy  deposit  as  well.  We  may  perhaps  have  noticed 
how  drops  of  dew  lie  upon  the  leaves  without  soaking 
in,  so  that  when  the  dew  is  shaken  off,  the  leaves  are 
dry.  This  is  especially  noticeable  on  some  shiny 


Water  93 

leaves,  but  also  on  some  mealy-looking  ones,  as,  for 
instance,  cabbage  leaves ;  and  in  both  cases  it  is  the 
waxy  substance  in  or  upon  the  skin  of  the  leaf,  which 
not  only  prevents  water  from  soaking  in,  but  also 
prevents  all  but  a  very  small  quantity  of  moisture  from 
being  drawn  out. 

Then,  if  water  is  constantly  passing  off,  and  that  in 
considerable  quantities,  how  does  it  escape  ?  A  little, 
as  we  have  said,  passes  off  through  the  whole  surface, 
but  the  bulk  finds  its  way  out  through  special  openings, 
pores,  or  mouths,  to  which  the  name  of '  stomata '  has 
been  given.  These  pores  are  extremely  minute  open- 
ings in  the  outer  skin  of  leaf  and  stem,  and  vary  very 
greatly  in  size  and  number  in  different  plants.  It  is 
through  them  that  used-up  air  and  water  in  the  form 
of  vapour  are  allowed  to  escape. 

The  process  by  which  vapour  is  given  off  through 
the  leaf  pores  is  called  '  transpiration,'  and  is  not  the 
same  thing  as  evaporation,  though  like  it,  it  proceeds 
more  quickly  in  hot  dry  weather.  But  evaporation 
goes  on — or,  in  other  words,  the  air  sucks  moisture — 
from  the  whole  surface  of  a  plant — from  trunk,  stem 
and  leaves  more  or  less,  and  would  suck  much  more 
than  it  does  if  it  were  not  prevented. 

Transpiration,  on  the  other  hand,  is  confined  to  the 
leaf-pores,  and  is  the  process  by  which  the  plant  parts 
by  its  own  action,  so  to  say,  with  its  superfluous 
moisture.  In  evaporation  the  plant  is  merely  acted 
upon  by  the  air ;  the  moisture  is  sucked  out  as  it  is 
sucked  from  a  wet  sheet  hung  out  to  dry,  or  a  piece  of 
dead  wood.  In  transpiration  the  moisture  passes  out 
through  the  proper  openings,  and  the  plant  itself  acts, 
or  at  least  discharges  one  of  the  natural  functions  of 


94  Water 

its  being.  Evaporation  may  continue  in  a  dead  plant, 
but  only  a  living  plant  transpires. 

Both  processes  are  affected  by  the  weather,  however, 
and  both  in  a  similar  way. 

Nothing,  we  know,  dries  on  a  very  damp  day, 
because  the  more  moisture  the  air  contains,  the  less  it 
can  take  up ;  or,  in  other  words,  evaporation  proceeds 
slowly  in  moist  air.  So,  too,  transpiration  almost  or 
quite  ceases  in  damp  weather,  or  when  the  leaves  are 
wet.  But  both  go  on  more  briskly  in  the  sun,  in  dry 
air,  and  more  especially  in  a  drying  wind. 

The  leaf-pores  by  which  transpiration  proceeds  are 
usually  more  abundant  on  the  under  surface — the 
shady  side — of  the  leaves,  and  are  few  or  altogether 
wanting  on  the  upper  surface,  where  they  would  be 
exposed  to  the  sun,  and  water  might  pass  off  too 
rapidly.  In  moist,  shady  situations  there  is  no  danger 
of  too  much  transpiration,  and  plants  growing  in  these 
not  only  have  more  leaf-pores  than  others,  but  can 
also  have  them  without  risk,  both  on  the  under  and 
upper  surface  of  the  leaves,  for  here  transpiration  goes 
on  more  slowly,  and  the  loss  of  water  is  also  easily 
made  up. 

Thick,  fleshy  leaves  have  the  fewest  leaf-pores,  and 
thick,  fleshy  leaves  are  particularly  characteristic  of 
hot  countries,  where  plants  can  afford  to  lose  but 
little  of  the  scanty  supply  of  water  which  comes  to 
them. 

Many  leaves  which  are  alike  on  both  sides  have 
about  an  equal  number  of  pores  above  and  below ;  but 
when  there  is  any  difference,  as,  for  instance,  where 
one  side  is  dull  and  the  other  glossy,  the  dull  side, 
which  is  also  the  under  side,  has  the  larger  number  of 


Water  95 

pores.  The  leaves  of  the  laurustinus  have  no  leaf- 
pores  at  all  on  their  shiny,  upper  surface,  neither  have 
those  of  the  lilac ;  while  those  of  the  carnation,  which 
show  no  such  difference  as  these  do,  have  about  an 
equal  number  on  each  side.  Some  leaves  have  as 
many  as  170,000  pores  to  the  square  inch,  but  this 
seems  to  be  the  largest  number.  An  apple  leaf 
of  ordinary  size  has  about  100,000  leaf-pores  alto- 
gether. 

The  size  of  the  pores  varies  very  much,  but  at  their 
largest  they  are  so  minute  as  entirely  to  exclude  the 
very  finest  dust.  Those  of  the  white  lily,  for  instance, 
which  are  called  '  remarkably  large,'  measure  only  one 
4,25oth  part  of  an  inch  across. 

Hard,  evergreen  leaves,  such  as  those  of  the  pine, 
are  like  the  thick,  fleshy  ones  in  this,  that  they  have 
but  few  leaf-pores,  and  lose  but  little  water  except 
through  these  openings.  For  pines  grow  in  very  dry, 
sandy  soils,  and  often  in  elevated  situations,  where  the 
air,  though  cold,  is  exceedingly  dry  and  drying,  and 
they  therefore  need  as  much  protection  as  plants 
which  grow  in  hot,  dry  climates. 

Many  and  various  are  the  devices  by  which  evapora- 
tion is  checked  and  controlled,  even  in  temperate 
latitudes,  lest  the  plant's  need  of  water  should  exceed 
the  supply.  For  it  must  be  remembered  that  air  has 
an  immense  appetite  for  water;  the  drier  it  is  the 
more  it  takes  up,  but  it  goes  on  sucking,  if  allowed,  as 
long  as  it  is  in  contact  with  anything  containing 
moisture  until  it  can  hold  no  more. 

It  is  this  which  makes  the  misery  of  an  east  wind, 
which  is  a  very  dry  wind,  as  well  as  a  cold  one,  and 
sucks  up  moisture  Wherever  it  can,  not  only  from  vege- 


96  Water 

tation,  but  from  the  bodies  of  animals,  drying  the  skins 
of  human  beings,  as  the  hot,  dry  air  of  the  desert  dries 
them,  though  in  less  degree. 

Since  three-fourths  of  the  weight  of  most  plants,  and 
more  of  many,  is  made  up  of  water,  the  air  would  be 
always  sucking  at  them,  if  not  prevented.  As  things 
are,  however,  though  some,  generally  very  small, 
amount  of  water  is  sucked  by  the  air  from  the  whole 
surface  of  a  plant,  as  we  have  said,  its  escape  is  con- 
fined, as  far  as  may  be,  in  most  cases,  and  especially  in 
dry  climates,  to  the  legitimate  openings,  the  pores 
made  for  this  purpose. 

Soft,  thin  leaves  lose  water  by  evaporation  from  the 
whole  surface,  and  have  a  large  number  of  pores  as 
well,  but  they  grow  in  situations  where  they  can 
easily  make  up  the  loss.  All  leaves,  however,  have 
some  protection  more  or  less  in  the  skin  which 
covers  them,  this  skin  being,  moreover,  as  we  have 
said,  impregnated  with  wax,  which,  though  com- 
monly invisible,  often  appears  as  a  shiny  coating,  or 
as  'bloom.' 

A  cabbage,  for  instance,  has  a  mealy  look  about  it, 
as  if  it  had  been  dusted  with  flour ;  many  grasses, 
acacias,  and  the  now  well-known  Australian  gum-tree 
or  eucalyptus,  have  a  similar  appearance,  and  when 
this  '  bloom '  is  examined  it  is  found  to  consist  of 
minute  rods,  or  needles,  of  wax.  The  substance  forms 
a  regular  incrustation  on  the  stem  of  the  Peruvian 
wax  palm,  whose  native  land  is  one  of  the  most  rain- 
less regions  of  the  earth ;  and  there  is  nothing  more 
effectual  than  wax  for  excluding  air  and  preventing 
evaporation.  Honey  stored  in  wax-cells  is,  as  it  were, 
hermetically  sealed  up  and  preserved, 


Water  97 

With  the  wax  is  often  associated  resin,  which  acts  in 
a  similarly  protecting  way  apparently.  No  explanation 
indeed  has  hitherto  been  given  of  the  use  to  the  plant 
of  gums,  resins,  caoutchouc,  and  the  strong-smelling 
oils  frequently  found  in  leaves  ;  but,  as  water  in  which 
gum  or  any  other  substance  is  dissolved  evaporates 
more  slowly  than  pure  water,  it  seems  not  unlikely 
that  one  at  least  of  the  uses  of  these  substances  is  to 
check  the  escape  of  water.  And  this  seems  the  more 
probable  when  we  consider  that  aromatic,  as  well  as 
gum  and  resin-bearing,  plants  are  especially  charac- 
teristic of  deserts  and  dry  regions,  hot  or  cold.  Thus 
the  pine-tree  of  the  north  has  its  turpentine,  the 
eucalyptus  of  hot,  dry  Australia  its  oil,  and  the  acacias 
of  Africa  their  gums. 

Many  trees  and  shrubs  in  hot,  dry  countries  are 
protected  also  by  having  either  small  or  very  few 
leaves,  or  even  none  at  all. 

Where  the  air  is  constantly  damp,  as  it  is  in  many 
parts  of  the  tropics,  there  the  trees  may  boldly  venture, 
as  the  plantain  does,  to  spread  broad  leaves  many  feet 
square  to  the  sun,  for  the  water-supply  never  fails,  and 
the  air  is  not  outrageously  thirsty,  as  it  is  in  the  desert. 
But  in  those  parts  of  Australia  where  rain  is  scanty  and 
droughts  are  frequent,  there  the  leaves  are  not  only 
small,  as  we  have  said,  but  they,  most  of  them,  also 
protect  themselves  by  turning  only  their  edges,  not 
their  broad  sides,  to  the  sun ;  for  they  have  to  economize 
their  resources  as  much  as  possible.  This  is  par- 
ticularly the  case  with  many  species  of  Eucalyptus, 
some  of  which  turn  one  leaf-edge  to  the  earth  and  the 
other  to  the  sky,  or  stand  erect,  turning  one  edge 
towards  the  stem  and  the  other  away  from  it,  in  each 

7 


98  Water 

case  exposing  themselves  as  little  as  possible.  Their 
leaves,  too,  are  for  the  most  part  narrow,  and  so 
scantily  distributed  over  the  branches  that  an  Aus- 
tralian forest  has  none  of  the  deep  shade  which  the 
word  naturally  suggests  to  us. 

But  when  the  eucalyptus  is  transported  to  other 
lands,  where  it  has  plenty  of  deep,  rich  soil,  and 
moisture  in  abundance,  then  it  puts  on  more  foliage, 
showing  that  it  was  only  the  dry  heat  of  its  native 
climate  which  made  it  so  sparing  of  its  leaves. 

Most  of  the  many  species  of  acacia  found  in 
Australia  go  even  a  step  beyond  the  eucalyptus  in  the 
way  of  economizing  their  foliage,  and  give  up  having 
any  true  leaves  at  all  as  soon  as  they  are  full-grown. 
They  keep  their  leaf-stalks  indeed,  but  there  are  no 
leaves  at  the  end  of  them,  and  instead  there  are 
'  wings,'  or  narrow,  leaf-like  margins,  growing  out 
from  each  side  of  the  stalks.  Even  these  'wings'  do 
not  venture  to  face  the  sun,  but  turn  their  edges  to 
earth  and  sky. 

Acacias  are  especially  the  trees  of  deserts ;  they  are, 
indeed,  the  only  timber-trees  of  the  Arabian  Desert, 
and  they  abound  in  Africa,  as  also  in  Australia.  But 
wherever  they  grow  they  are  characterized  by  the 
lightness  of  their  foliage ;  and  of  the  Australian  species, 
which  number  something  under  three  hundred,  two 
hundred  and  seventy  drop  their  leaves  altogether  when 
they  are  grown  up,  and  merely  flatten  out  their  leaf- 
stalks as  described. 

None  of  the  Cactus  family — which  are  natives  of 
the  hot,  dry  regions  of  America,  North,  South,  and 
Central — make  any  attempt  at  having  leaves  or  even 
'  wings/  but  their  stems  are  flattened  out  and  do 


Water  99 

duty  instead.  The  stems,  too,  are  protected  against 
evaporation  by  being  enveloped  in  a  peculiar  leathery 
skin,  which  is  thickest  in  the  species  inhabiting  the 
hottest  and  driest  regions  ;  and  they  lose  little  water 
therefore,  except  through  the  pores,  which  are  but 
few  in  number.  Thus  protected,  they  not  only  exist, 
but  flourish,  in  dry  sand,  where  for  three-quarters  of 
the  year  they  are  exposed  to  the  blazing,  parching 
sun. 

The  tall,  fluted  columns  of  the  species  of  cactus 
called  the  '  Torch  Thistle/  sometimes  fifty  feet  high, 
are  to  be  seen  springing  out  of  crevices  in  the  hard 
rock,  and  standing  up  like  telegraph-posts  on  the 
mountains  and  in  the  rocky  valleys  all  over  the  hot, 
parched,  almost  desert  regions  of  New  Mexico. 

This  tall  cactus  seems  to  be  so  fully  protected  by  its 
thick  skin  that  it  may  venture  to  expose  its  whole 
surface  to  the  sun  without  risk ;  but  other  species  are 
less  bold,  and  keep  close  to  the  ground,  growing  in  the 
form  of  large  cushions  or  great  globular  masses,  and  so 
diminishing  the  extent  of  exposed  surface.  Some,  too, 
are  set  all  over  with  long,  slender,  needle-like  spines, 
and  are  also  covered  with  what  look  like  dense  masses 
of  floss  silk,  both  of  which  protect  the  plant  from  the 
hot  air  and  sun.  . 

But  though  these  special  means  of  defence  are  more 
striking  in  the  tropics  than  elsewhere,  they  are  em- 
ployed more  or  less  everywhere,  our  own  moist  land 
not  excepted.  Besides  the  bark,  and  the  cork,  and 
the  more  or  less  thick  skin  of  the  leaves,  and  the  wax, 
which  we  have  already  mentioned  as  the  ordinary 
means  by  which  evaporation  is  checked,  these  other 
measures  are  also  frequently  adopted  for  securing  the 


roo  Water 

same  end.  Our  plants  do  not  indeed  go  so  far  as  to 
drop  their  leaves  altogether,  but  some  of  them  do 
greatly  diminish  both  their  number  and  size  ;  and  some 
clothe  themselves  with  hairs,  partly,  as  it  would  seem, 
lest  they  should  be  deprived  of  too  much  moisture, 
though  partly  also,  probably,  as  a  protection  against 
insects.  An  example  or  two  of  these  must  suffice,  and 
we  will  take,  first,  that  of  the  Amphibious  Persicaria — 
a  particularly  interesting  plant,  as  it  grows  both  on 
land  and  in  water,  and  adapts  itself  to  its  situation  in 
a  very  marked  manner.  When  it  grows  in  water, 
where,  of  course,  it  does  not  matter  how  much  it  may 
lose,  it  has  smooth,  lance-shaped  leaves ;  but  when  it 
grows  on  land  the  leaves  are  narrower,  and  not  only 
this,  but  they  are  covered  as  well  with  a  quantity  of 
long  hairs,  pressed  close  upon  the  surface,  which  they 
protect  against  evaporation. 

Then  there  is  the  Sweet  Woodruff,  whose  lance- 
shaped  leaves  grow  in  whorls  of  eight,  for  the  plant 
dwells  in  moist,  shady  places,  where  there  is  no  risk  in 
having  many  leaves.  But  look  from  this  to  another 
member  of  the  family,  the  Quinsy  Wort,  and  what  do 
we  find  ?  The  leaves  are  very  narrow,  and  there  are 
but  half  as  many  cf  them.  Why  ?  Because  this  little 
plant  grows  on  dry  banks,  where  many  and  large 
leaves  would  be  dangerous  to  its  welfare. 

It  has  been  already  mentioned  that  the  Pine  family, 
which  thrive  in  dry,  sandy  soils,  have  hard,  needle-like 
leaves,  with  few  pores,  and  therefore  give  off  but  little 
water,  either  by  evaporation  or  transpiration  ;  and  it  is 
for  this  reason  that  the  air  in  a  pine  forest  in  summer 
has  none  of  the  coolness  which  one  finds  in  a  forest  of 
what  the  Germans  cal]  '  leaf-trees,'  The  '  needles  '  of 


Water  tot 

the  pine    they  do    not    consider  worthy  the    name 
of  leaves. 

Leaf-trees  are  continually  cooling  the  air  by  the 
moisture  which  they  give  up  to  it ;  but  the  pine- 
needles  have  so  few  pores,  and  are  so  very  much 
protected,  that  the  little  water  they  part  with  is  not 
enough  to  produce  any  appreciable  effect  upon  the  air. 

It  is,  perhaps,  hardly  necessary  to  do  more  than 
remind  our  readers  that  the  evaporation  of  water 
is  always  accompanied  by  the  absorption  of  heat,  or, 
in  other  words,  that  water  cannot  be  converted  into 
gas  or  vapour,  which  it  is  when  evaporated,  without 
using  up  heat.  Whether  it  be  the  heat  of  a  fire  or  the 
heat  of  the  sun,  it  is  all  the  same.  A  certain  amount 
of  heat  is  required  to  make  water  pass  from  the  liquid 
to  the  gaseous  state,  and  if  this  heat  be  taken  from  the 
air,  the  air  is  necessarily  by  so  much  the  cooler. 

And  this  brings  us  to  another  part  of  the  subject, 
the  question,  namely,  as  to  the  amount  of  water  given 
off  by  trees  and  other  plants,  notwithstanding  the 
various  ways  in  which,  as  we  have  seen,  they  are 
protected. 

We  have  distinguished  hitherto  between  the  two 
processes  of  evaporation  and  transpiration,  because 
they  are  distinct ;  the  one  being  due  to  the  action  of 
the  air,  and  the  other  to  the  action,  so  to  say,  of  the 
plant.  Evaporation  takes  place  whenever  air  comes 
in  contact  with  anything  moister  than  itself;  whether 
it  be  animal  or  vegetable,  whether  it  be  wet  earth  or 
damp  clothes,  from  all  it  draws  water,  and  by  its  own 
heat  converts  this  water  into  vapour.  The  other 
process,  transpiration,  is  that  by  which,  through  the 
pores — the  openings  left  in  the  skin  of  stem  and  leaf— 


to*  Water 

the  plant  gives  up,  in  a  regular,  systematic  manner, 
the  moisture  with  which  it  would  else  be  overcharged. 

But  in  both  cases  the  water  passes  off  into  the  air  in 
the  form  of  vapour ;  and  in  both  cases  it  passes  off  as 
nearly  pure  water,  all  mineral  matter  being  left  behind  ; 
in  both  cases  also,  the  amount  given  off  varies  with  the 
weather,  there  being  more  loss  on  a  hot,  dry,  sunny, 
or  windy  day,  than  on  a  damp,  dull,  still  one.  When, 
therefore,  we  consider  the  amount  of  water  which 
passes  off  into  the  air  from  a  plant  in  a  certain  time, 
it  is  generally  impossible  to  distinguish  between  that 
which  comes  through  the  whole  surface  and  that 
which  comes  through  the  pores ;  and  both  processes 
are  frequently  spoken  of  together  as  transpiration  or 
evaporation.  The  quantity  transpired  is,  however, 
usually  very  much  larger  than  the  quantity  evaporated. 

In  some  plants  it  is  occasionally  possible  to  see  the 
moisture  coming  from  the  leaf-pores,  as  it  escapes 
faster  than  the  air  can  evaporate  it.  This  is  the  case 
with  many  grasses,  especially  the  maize,  which  may 
be  seen  studded  with  actual  drops  of  water. 

A  grass-plant  gives  up  its  own  weight  of  water  in 
the  course  of  twenty- four  hours,  in  hot,  dry  weather; 
and  a  square  foot  of  turf  will  yield  more  than  i£  pints 
of  water  in  this  time.  But  a  square  foot  of  long 
pasture-grass  gives  off  nearly  4^  pints,  or  as  much  as 
106  tons  of  water  to  the  acre ! 

The  larger  the  surface,  the  larger  of  course  the 
amount  of  water  which  passes  off  from  it ;  and  there- 
fore the  extent  of  surface  exposed  is  a  matter  of  great 
importance,  though  it  is  also  one  which  we  are  very 
likely  to  overlook,  at  least  in  many  cases.  Of  course 
we  can  all  see  that  a  tropical  plantain  with  its  broad, 


Water  103 

large  leaves,  has  a  considerable  surface  exposed  to  sun 
and  air ;  and  so  with  other  conspicuously  large-leaved 
plants.  But  when,  instead  of  a  few  large  leaves,  a 
plant  has  many  small  ones,  it  is  not  so  easy  to  realize 
what  the  whole  surface  may  amount  to. 

A  sun-flower,  for  instance,  has  leaves  of  a  good  size, 
and  yet  it  is  rather  surprising  to  find  that  in  a  plant 
only  three  feet  and  a  half  high,  the  whole  leaf-surface 
may  amount  to  more  than  thirty-two  square  feet ! 
One  specimen  of  this  size  was  found  to  give  up  from  a 
pint  to  a  pint  and  a  half  of  water  during  a  day  of  twelve 
hours.  The  sun-flower  is  quite  outdone  by  the  cabbage* 
however,  one  specimen  of  which  gave  off  nearly  two 
pints  and  a  half  in  twenty-four  hours,  and  that  from 
leaves  which,  had  they  been  spread  out,  would  have 
covered  only  nineteen  square  feet.  We  have  seen  how 
well  the  cabbage  is  protected  by  its  wax  coating  against 
evaporation,  so  that  almost  the  whole  of  this  amount 
is  given  off  by  the  plant's  own  action.  The  camellia  is 
much  less  thirsty;  it  has  fewer  pores,  and  its  thick, 
glossy  leaves  are  so  efficiently  protected,  that  half  an 
ounce  of  water,  ^  pint  to  the  square  foot  of  foliage, 
was  all  that  one  plant  gave  up  in  a  day  and  night. 

These  calculations  are  comparatively  simple;  but, 
when  we  come  to  trees,  who  would  venture  to  guess  at 
the  extent  of  surface  exposed  to  the  air  and  sun  by  the 
leaves  upon  an  elm?  We  look  up  at  the  quivering 
multitudes,  and  feel  as  if  it  were  hopeless  for  anyone 
even  to  attempt  to  count  them ;  it  is  too  bewildering ! 

Yet  the  calculation  has  been  made,  and  the  leaves 
on  a  not  very  large  elm-tree  are  said  to  be  about 
7,000,000,  which  would  give  a  surface  of  about  200,000 
square  feet,  or  five  acres  ! 


104  Water 

From  the  whole  of  these  five  acres  of  green  surface, 
water  passes  off  into  the  air  in  the  form  of  vapour,  to 
the  amount  of  seven  tons  and  three-quarters  during 
each  twelve  hours  of  clear,  dry  weather. 

But  if  this  is  the  quantity  returned  to  the  air  by  a 
single  tree  of  only  moderate  size,  how  large  must  be 
the  amount  received  from  a  wood  or  forest,  containing 
hundreds  or  thousands  of  trees ! 


IX. 

DESERTS 

FROM  what  has  been  already  said,  it  is  evident  that 
every  tree,  every  plant,  every  spire  of  grass  indeed,  is 
a  pumping  apparatus  on  a  larger  or  smaller  scale,  by 
which  a  portion  at  least  of  the  water  which  descends 
from  the  clouds  begins  to  mount  up  again  almost  as 
soon  as  it  has  fallen. 

Plants  give  up  to  the  air,  chiefly  by  transpiration 
through  their  leaf- pores,  but  partly  also  by  evaporation 
from  their  whole  surface,  nearly  as  much  water  as  is 
taken  up  by  their  roots — nearly,  but  not  quite — for,  as 
long  as  they  are  growing,  they  need  some  water  for 
the  formation  of  new  shoots  and  leaves.  The  quantity 
is  not  much  in  itself,  though  water  makes  up  a  large 
part  of  the  weight  of  most  plants.  But  it  is  quite  clear 
that,  without  water,  they  cannot  grow  at  all. 

Provided  a  plant  has  a  plentiful  supply  of  water, 
enough,  that  is,  to  make  up  for  what  it  loses,  it  does 
not  seem  to  matter  how  much  it  transpires.  Some 
plants  thrive  perfectly  well  in  dry  air — where  they  give 
off  moisture  constantly  and  rapidly — if  only  their  roots 
be  kept  in  damp  soil ;  and  others  thrive  equally  well  in 
comparatively  dry  soil,  provided  the  air  be  damp  enough 


io6  Deserts 

to  check  transpiration  and  allow  them  to  retain  most 
of  the  moisture  they  draw  up.  But,  when  once  a  plant 
has  thoroughly  flagged,  the  case  is  different.  Then, 
nothing  short  of  water  supplied  to  the  roots  will  be 
sufficient  to  revive  it.  Damp  air  will  be  of  no  use; 
neither  will  the  heaviest  dew  avail  anything.  The 
roots,  and  the  roots  only,  can  furnish  the  necessary 
supply. 

Of  course  every  substance — even,  as  we  have  seen, 
the  hardest  rocks — will  absorb  some  amount  of  water 
when  actually  steeped  in  it ;  and  so,  if  a  withered  shoot 
is  kept  soaking  in  water,  it  will  absorb  a  certain  quantity 
in  time,  as  any  piece  of  dead  wood  does.  But  leaves 
and  stems  have  little  or  no  power  of  absorbing  moisture 
from  the  air. 

This  is  the  general  rule,  to  which  there  are  a  few, 
but  only  a  few,  exceptions ;  lichens,  which  have  no 
roots,  do  draw  moisture  from  the  air,  and  would  be 
badly  off  if  they  could  not,  considering  the  bare  rocks 
upon  which  they  grow.  Mosses,  too,  which  grow 
where  there  is  little  or  no  soil,  also  supply  themselves 
with  moisture  from  the  air  to  a  great  extent ;  and  so  it 
is  believed  do  plants,  such  as  the  mistletoe,  which  grow 
upon  others. 

But  still  the  general  rule  holds  good ;  leaves  have 
little  or  no  power  of  absorbing  moisture  either  from  the 
air  or  from  water  poured  upon  them. 

And  yet,  how  the  drooping  leaves  revive  on  a  dewy 
evening,  or  in  a  shower  of  rain,  or  even  under  the 
influence  of  a  shower  from  the  watering-pot !  The 
water  cannot  surely  have  had  time  to  reach  the  roots, 
and  then  to  travel  up  the  stem. 

Water  certainly  does  travel  upwards  with  amazing 


Deserts  107 

rapidity  in  some  plants,  as  will  be  seen  presently  ;  but 
when  leaves  revive  on  a  dewy  evening,  or  during  a 
shower,  it  is  not  because  they  have  drunk  in  any  of 
these  fresh  supplies.  Moisture  is  constantly  passing  up 
to  them  in  larger  or  smaller  quantities  from  below ;  but 
they  part  with  it  nearly  as  fast  as  they  receive  it 
generally,  and  faster  than  they  receive  it  in  dry  weather. 
It  is  the  want  of  sufficient  moisture  which  makes  them 
droop  and  renders  them  flabby.  But  when  the  dew 
falls  on  them  transpiration  ceases,  or  nearly  so ;  they 
are  able  to  keep  nearly  all  the  moisture  sent  up  to 
them,  and  so  they  swell  out  again  and  stiffen,  and  hold 
themselves  up. 

A  similar  effect  may  be  seen  even  in  cut  shoots  which 
have  been  allowed  to  fade,  and  are  then  placed  in  very 
damp  air.  No  moisture  is  taken  up ;  quite  the  con- 
trary; the  continued  decrease  in  their  weight  shows 
that  moisture  is  passing  off  into  the  air,  little  by  little, 
all  the  time ;  but  stem  and  leaves  are  losing  it  very 
much  more  slowly  than  they  did  in  ordinary  air  ;  and 
as  water  from  the  lower,  older  parts  of  the  stem  con- 
tinues to  rise,  as  it  did  before  the  shoot  was  severed 
from  the  tree,  so  the  younger  parts  at  the  top,  the 
leaves  and  buds,  are  refreshed  and  revived.  Of  course, 
this  can  go  on  only  for  a  time,  so  long,  that  is,  as  any 
of  the  original  moisture  is  left  in  the  stem  ;  and  when 
this  is  exhausted  the  leaves  droop  as  before,  and  at  last 
wither  entirely. 

And  now  to  gain  some  idea,  if  we  can,  of  the  rate  at 
which  water  travels  upwards  from  the  roots  to  the 
leaves  of  a  plant.  This  of  course  varies  enormously  in 
different  plants,  because  some  transpire  so  very  much 
more  than  others ;  and  it  also  varies  greatly  at  different 


io8  Deserts 

seasons  of  the  year,  according  as  the  plant  is  growing, 
or  putting  out  buds  and  leaves,  or  not. 

Experiments  made  by  watering  plants  with  coloured 
solutions  are  not  very  satisfactory,  because  the  colour- 
ing matter  may  be  caught  and  entangled,  while  the  water 
moves  on  without  them.  Still,  it  is  interesting  to  learn 
that  in  the  case  of  a  white  iris,  which  was  watered  with 
a  blue  solution,  the  white  petals  were  streaked  with 
colour  in  from  ten  to  fifteen  hours. 

A  more  trustworthy  experiment  made  upon  a  willow 
seemed  to  show  that  the  water  in  this  case  rose  from 
the  roots  at  a  very  much  more  rapid  rate — thirty-four 
inches  an  hour.  But  the  willow,  having  its  roots  always 
in  or  near  water,  has  no  need  to  be  economical. 

In  a  plant  of  maize,  whose  roots  were  in  earth,  the 
rate  was  much  less,  being  little  more  than  14  inches 
per  hour ;  in  a  sunflower  it  was  25  inches ;  but  in  a 
tobacco-plant  it  was  47^  inches  per  hour.  The  tobacco 
transpires  so  freely  that  its  leaves  droop  as  soon  as 
gathered,  and  these  experiments  were  made  in  such  a 
way  as  to  encourage  transpiration  to  the  utmost. 

In  some  plants  the  sap  rises  with  extraordinary 
rapidity;  as,  for  instance,  the  Water-liana.  This  is 
one  of  the  many  gigantic,  rope- like  creepers  or  'vines  ' 
of  tropical  America,  and  owes  its  name  to  the  fact  that 
clear,  cool  water  fit  for  drinking  can  be  obtained  from 
its  stem — by  those,  at  least,  who  know  how  to  pro- 
ceed. 

These  climbers  mount  up  among  the  trees  far  over- 
head, so  that  to  cut  off  the  top  of  one  is  quite  im- 
possible. A  length  of  some  seven  feet  has  to  be  cut 
out  where  it  is  within  reach,  and  this  piece  will  yield 
about  a  pint  of  water ;  but  it  must  be  cut  first  at  the  top, 


Deserts  109 

otherwise,  if  cut  first  near  the  ground,  almost  the  whole 
of  the  water  will  have  rushed  away  into  the  vine  high 
overhead  before  the  second  cut  can  be  made. 

This  plant  therefore  seems  to  dispose  of  a  pint  of 
water  in  less  than  a  minute,  and  almost  all  by  tran- 
spiration, since  the  quantity  evaporated  and  the 
quantity  required  for  growth,  in  one  minute,  must  be 
exceedingly  small.  At  this  rate  the  liana  pumps  up 
from  the  ground  60  pints  of  water  in  an  hour — 720 
pints,  or  go  gallons,  in  a  day  of  twelve  hours. 

In  early  spring,  when  the  sap  is  beginning  to  rise,  the 
sugar-maple  will  sometimes  yield  as  much  as  seven  or 
eight  gallons  every  day  for  three  weeks,  and  this,  of 
course,  does  not  represent  more  than  a  small  portion 
of  the  water  which  the  tree  has  taken  up,  as  it  is  only 
tapped,  not  drained  of  moisture.  But  the  maple  is 
far  outdone  by  the  Black  Birch,  another  of  the 
American  trees  from  which  sugar  is  made ;  for  one 
specimen  of  this  yielded,  in  four  or  five  weeks,  the 
extraordinary  quantity  of  about  1,890  gallons.  And 
this,  like  the  sap  yielded  by  the  maple,  is  only  a  part, 
and  a  small  part,  of  the  moisture  which  the  tree  has 
drawn  from  the  earth,  and  would  in  the  natural  course 
of  things  return  to  the  air,  diminished  only  by  the  small 
supply  needed  for  fresh  shoots  and  leaves. 

But  the  amount  of  water  which  a  plant  takes  up  does 
not  depend  solely  on  the  soil  and  climate  in  which  it 
grows,  but  also  on  the  plant  itself.  There  is  a 
wonderful  difference  in  the  power  which  plants  possess 
of  supplying  themselves  with  food  and  water.  Just  as 
one  man  will  live,  and  even  thrive,  where  another  would 
starve,  so  it  is  with  vegetables.  The  lichen  makes  a 
living  off  the  bare  rock,  where  nothing  else  can  grow  \ 


1 10  Deserts 

and  the  ice-plant  carpets  some  of  the  most  arid  rocks 
of  Greece,  even  after  months  of  drought,  and  looks, 
too,  just  as  deliciously  cool  as  ever,  its  fleshy  leaves 
being  still  covered  with  their  characteristic  '  frosting,' 
against  which  the  hottest  sun  is  powerless.  On  closer 
examination  the  coating  of  *  frost '  turns  out  to  be 
composed  of  innumerable  globules  of  water  contained 
in  the  surface-cells — the  skin — of  the  leaf.  A  prick  with 
a  needle  shows  that  these  globules  are  just  tiny  bladders 
filled  with  water ;  but  this  skin  is  so  exceedingly  thin, 
and  so  perfectly  transparent,  that  it  is  a  mystery  how 
the  plants  manage  to  keep  their  moisture ;  and  it  is 
often  no  less  a  mystery  how  they  manage  to  obtain  it 
in  the  first  instance. 

An  English  meadow,  again,  would  wither  and  turn 
brown  if  it  were  left  un watered  beneath  the  fierce  heat 
of  a  tropical  sun,  but  the  grasses  of  the  Kalahari  desert 
of  South  Africa  remain  surprisingly  green,  though 
they  get  but  one  or  two  falls  of  rain  in  the  course  of  the 
whole  year.  Sometimes  they  get  no  rain  at  all  for  a 
twelvemonth;  but  even  then,  when  they  are  the  colour 
of  hay,  they  are  equal  to  hay  of  ordinary  quality  as 
fodder  for  cattle,  and  hence  are  of  course  still  very 
valuable.  The  wonder  is  how  they  manage  to  keep 
any  life  at  all,  and  any  nourishment  in  them,  after  so 
many  months  of  burning  drought. 

In  parts  of  Texas,  where  also  rain  is  quite  the  ex- 
ception, the  grass  is  often  destroyed  during  the  hot 
months  ;  but  other  green  things  contrive  to  exist,  and 
these  supply  its  place  to  the  cattle.  Timber  is  scarce 
in  these  parts ;  but  within  the  last  twenty  years 
thickets  of  '  mesquite  '  have  sprung-  up,  and  now  cover 
miles  of  prairie,  where  formerly  there  were  none.  And 


Deserts  1 1 1 

a  most  valuable  tree  the  '  mesquite '  is,  not  only  for 
fuel,  fences,  and  for  the  framework  of  houses,  but  for 
food.  Its  light  foliage  takes  the  place  of  grass  during 
the  hot  season,  while  its  beans  supply  the  cattle  with 
abundant  food  in  winter ;  and  it  is  enabled  to  bear  the 
drought  by  the  fact  that  it  has  huge  roots,  which  weigh 
hundreds  of  pounds  when  the  tree  is  only  a  few  feet 
high. 

But  the  Prickly  Pear  cactus  is  almost  equally  useful, 
so  far  as  the  cattle  are  concerned,  and  it  covers 
prairies  so  vast  that  the  supply  is  simply  inexhaustible. 
In  spite  of  drought,  and  heat,  and  dry  soil,  the  thick 
stem-like  leaves,  or  leaf-like  stems,  hold  an  enormous 
quantity  of  moisture,  and  when  the  thorns  have  been 
burnt  off  even  sheep  can  live  and  grow  fat  upon  it. 
For  horses  and  cows  it  is  split  open,  and  they  eat  out 
the  inside,  which  is  so  succulent  as  to  answer  the 
purpose  of  drink  as  well  as  food.  One  can  hardly 
imagine  any  other  way  in  which  water  could  be  so 
successfully  stored  in  these  arid  districts  as  within  the 
thick  leathery  skin  of  the  cactus. 

But  the  gourd  family  are  almost  as  wonderful  in  the 
way  in  which  they  manage  to  appropriate  and  keep 
possession  of  water,  even  under  the  driest  circum- 
stances. 

A  pumpkin  is  all  water,  with  the  exception  of  five 
and  a  half  per  cent,  of  its  weight ;  and  yet  large  pump- 
kins may  be  seen  growing  in  what  looks  like  nothing 
but  sand.  To  be  sure,  their  thick  rinds  enable  them  to 
keep  the  water  when  they  get  it,  and  sand  is  liberal  in 
the  way  of  parting  with  its  moisture  ;  but  even  so, 
knowing  how  very  watery  they  are,  it  is  strange  to  see 
them  growing  in  such  dry  soil.  Plants  of  this  kind, 


H2  Deserts 

however — gourds  and  melons — are  especially  charac- 
teristic of  so-called  '  desert '  regions,  which  are  exposed 
to  long-continued  droughts. 

Whenever  there  is  more  rain  than  usual  vast  tracts  of 
desert  land  in  South  Africa  are  covered  with  melons, 
which  provide  food  and  drink  both  for  man  and  beast. 
The  sama,  or  wild  water-melon  of  the  Kalahari,  grows 
in  great  abundance  in  many  parts  of  this  desert ;.  and 
the  fruit,  which  remains  good  for  a  year  in  dry  seasons, 
aifords  the  natives  almost  their  only  supply  of  water 
when  they  are  journeying  across  this  rainless  region. 
Evidently,  therefore,  the  sama  is  able  to  make  the 
most  of  its  limited  opportunities,  and  can  not  only 
appropriate,  but  also  keep,  moisture,  where  most  plants 
would  simply  perish  of  thirst. 

Trying  as  are  the  droughts  of  the  South  African 
desert,  they  are  less  severe  than  those  of  Australia,  for 
at  all  events  such  rain  as  does  fall  is  kept,  arid  sinks 
into  the  sub-soil,  there  being  no  rivers  to  drain  it  away ; 
whereas  in  Australia  the  rivers  quickly  carry  it  off 
again.  Even  here,  however,  some  trees,  and  among 
them  the  eucalypti,  manage  to  store  water  in  their 
roots ;  and  from  this  supply  the  natives  were  in  the 
habit  of  helping  themselves  in  time  of  need.  The  long 
side  roots  were  laid  bare,  as  much  as  twenty  or  thirty 
feet,  and  divided  into  short  lengths,  from  which  water 
dripped  at  once,  clear,  cool,  and  free  from  any 
unpleasant  taste  or  smell. 

How  the  water  remains  so  cool,  buried  only  from 
six  to  twelve  inches  beneath  the  burning  surface,  is  one 
of  the  many  mysteries  connected  with  the  great  mystery 
of  life. 

Water  in  a  pipe,  from  which  there  was  little  or  no 


Deserts  113 

evaporation,  and  water  in  a  dead  root,  would  speedily 
grow  warm  under  similar  circumstances.  Water  in  a 
porous  vessel  keeps  cool,  indeed,  in  the  hottest  sun, 
because  the  vessel  is  porous,  and  water  is  constantly 
passing  through  it  and  being  turned  into  vapour ;  with 
the  result  that  the  air  immediately  surrounding  the 
vessel  is  being  constantly  cooled.  The  water  is  turned 
into  vapour  by  means  of  the  heat  abstracted  from  the 
air. 

But  the  water  in  the  roots  of  the  eucalyptus  is  not 
kept  cool  by  evaporation ;  else,  in  time  of  drought,  it 
would  be  evaporated  altogether.  Besides,  the  juice  of 
the  hard,  leathery-skinned  pomegranate  is  cool  on  the 
hottest  day;  so,  too,  is  that  of  the  melon,  with  its 
thick  rind ;  and  the  abundant  juice  of  the  thick-skinned 
mango  feels  as  cold  as  iced  water,  even  under  the 
blazing  sun  of  Ceylon  ;  though  the  evaporation  from 
any  one  of  these  must  be  very  slight  indeed. 

Moreover,  the  coolness  lasts  only  while  the  fruit 
remains  on  the  plant,  and  disappears  in  a  few  minutes 
after  it  is  gathered.  It  must,  therefore,  be  quite 
independent  of  evaporation,  and  the  temperature  of  a 
living  plant's  juices  must  be  like  the  temperature  of 
the  blood  in  men  and  animals,  quite  independent  of 
climate. 

The  ordinary  temperature  of  the  blood  of  human 
beings  (98°  F.)  remains  the  same  whether  they  live 
under  the  equator  or  in  the  Arctic  regions. 

And  so  it  is  with  plants.  They  are  cold-blooded,  so 
to  say,  and  cold-blooded  they  remain,  even  when  sur- 
rounded by  hot  air,  as  long  as  they  are  alive.  When 
they  are  dead  their  temperature  soon  rises  or  falls, 
according  as  the  surrounding  air  is  hot  or  cold.  But 

8 


ii4  Deserts 

if,  while  alive,  the  temperature  of  their  sap  were 
affected  by  climate,  or  by  the  changes  of  summer  and 
winter,  day  and  night,  then  not  only  would  it  be  con- 
stantly frozen  in  the  far  north,  and  not  far  short  of 
boiling  in  the  tropics ;  but  the  sap  of  an  acacia  of  the 
desert  might  freeze  by  night  and  almost  boil  by  day — 
a  sudden  and  violent  change,  which,  as  has  been 
shown,  wears  out  the  very  rocks. 

But  to  return  to  the  '  deserts/  by  which  we  are  to 
understand  those  regions  where  water  is  scarce, 
drought  frequent,  and  where  vegetation,  though  seldom 
or  never  entirely  absent,  is  more  or  less  scanty,  and 
more  or  less  peculiar,  because  it  is  especially  adapted 
to  the  special  circumstances  of  its  situation. 

The  soil  of  the  desert  may,  or  may  not,  be  poor,  but 
it  is  the  want  of  water  which  renders  these  regions 
comparatively  barren. 

Well-watered,  the  Kalahari  desert  might,  it  is  said, 
be  one  of  the  richest  grazing  lands  in  the  world ;  and 
the  utter  barrenness  of  certain  tracts  of  the  Sahara  is 
owing  merely  to  the  lack  of  rain,  for  the  soil  beneath 
the  sand  is  actually  rich,  and  is  not  only  quite  capable 
of  supporting  vegetable  life,  but  is  extremely  fertile 
wherever  there  is  moisture. 

The  other  marked  characteristic  of  desert-lands  is 
the  dearth,  if  not  absence,  of  trees,  and  the  question 
we  have  now  to  consider  is  whether  these  two  charac- 
teristics— the  want  of  water  and  the  scarcity  of  all 
vegetation,  but  especially  of  trees — are  brought  about 
the  one  by  the  other. 

Vegetation  cannot  thrive,  though  it  may  manage  to 
exist,  without  a  regular  supply  of  water ;  but  does 
vegetation  bring  rain  or  increase  the  rainfall  ? 


Deserts  115 

There  is  no  doubt  whatever  that  where  forests  have 
been  recklessly  destroyed  there  the  climate  has  been 
most  seriously  injured.  The  Ceylon  coffee-planters 
cut  down  forests  to  make  more  room  for  their  planta- 
tions, and  many  of  them  were  ruined  in  consequence. 
The  trees  were  gone,  but  so,  to  a  large  extent,  was  the 
rain  also  ;  and  the  additional  space  gained  was  value- 
less, for  the  coffee  could  not  grow  for  lack  of  moisture. 

So,  also,  the  destruction  of  the  olive-trees  in  Pales- 
tine has  diminished  the  rainfall  there,  and  with  the 
rainfall  the  productiveness  of  the  land,  for  centuries 
past.  Now  that  trees  have  been  planted  again  the 
rain  is  said  to  be  returning. 

So  much,  then,  is  certain  :  cut  down  forests  and  you 
will  have  less  rain ;  and,  though  the  natives  of 
Namaqua  Land,  South  Africa,  attributed  the  great 
diminution  in  their  rainfall  to  the  presence  of  the 
missionaries,  others  had  no  hesitation  in  ascribing  it  to 
their  own  wasteful  way  of  cutting  wood. 

But  though  loss  of  forest  brings  loss  of  rain,  it  is 
difficult  to  say  precisely  how  the  change  is  brought 
about,  and  whether  rain  is  actually  caused  by  transpira- 
tion or  not. 

Wherever  there  is  vegetation,  be  it  grass  or  be  it 
forest,  there,  as  has  been  shown,  large  quantities  of 
water  are  constantly  passing  off  into  the  air  in  the  form 
of  vapour.  And  the  amount  is  large,  not  merely  con- 
sidering the  means  by  which  it  is  pumped  up,  but  it  is 
large  actually  ;  very  large,  when  we  compare  it  with  the 
amount  of  rain  which  falls. 

For  instance,  from  the  record  kept  at  Greenwich  it 
appears  that  during  July,  our  wettest  month,  the 
average  fall  of  rain  is  something  under  three  hundred 


n6  Deserts 

tons  to  the  acre,  or  under  three  inches — three  hundred 
tons  during  the  whole  month,  or  less  than  ten  tons  each 
day.  But  an  acre  of  pasture-grass  actually  gives  up 
more  than  ten  times  this  quantity  in  the  course  of 
twenty -four  hours — 106  tons — that  is  to  say,  in  a  single 
day  and  a  night.  So  that  an  acre  of  pasture  which 
has  received  three  hundred  tons  of  rain  in  a  month, 
gives  up  more  than  three  thousand  tons  in  the  same 
time. 

The  question  as  to  where  this  immense  quantity 
comes  from  will  have  to  be  considered  later.  At 
present  we  are  concerned  only  with  the  fact  that  so 
much  water  is  returned  to  the  air.  Whether  it  falls 
again  on  the  same  spot  is  another  matter,  and  we  have 
no  proof  that  it  does  so.  It  may  do  so  under  certain 
circumstances,  or  it  may  be  carried  away  by  the  wind 
and  fall  elsewhere,  perhaps  close  by,  or  perhaps  a  long 
way  off. 

But  if  the  air  immediately  over  a  certain  district  is 
being  constantly  cooled  by  the  evaporation  day  after 
day  of  large  quantities  of  water,  does  this  produce  no 
effect  upon  the  air  above  ? 

What  happens  when  water  is  boiled  over  a  fire  ? 
Clouds  of  visible  vapour  rise  from  it,  which  we  com- 
monly call  *  steam.'  They  are  not  properly  steam, 
however,  for  steam  is  invisible.  These  are  clouds,  true 
clouds,  consisting  of  minute  globules  of  water,  steam 
made  visible,  converted  into  water  again  by  coming 
into  contact  with  the  air  of  the  room,  which  is  cooler 
than  that  within  the  kettle. 

As  heat  converts  water  into  gas  or  steam,  so  cold 
turns  it  back  into  water  again.  So  when  the  earth  is 
chilled  at  night  the  moisture  of  the  air  is  also  chilled 


Deserts  117 

on  a  large  scale,  and  dew  is  formed— first  on  grass  and 
leaves,  because  they  are  cooler  than  the  soil. 

If  this  be  so,  then  when  a  current  of  warm  moist  air 
comes  in  contact  with  the  cool  air  over  a  forest,  or 
over  acres  of  pasture,  will  not  some  of  its  moisture  be 
condensed  into  a  cloud,  as  the  steam  from  a  kettle  is 
condensed  into  a  cloud  when  it  escapes  into  the  air, 
and  may  not  this  cloud  discharge  itself  upon  the  grass 
or  the  trees  ? 

Of  course  the  cloud  may  be  carried  away;  but  it 
seems  likely  that,  in  some  cases  at  all  events,  it  will 
water  the  district  above  which  it  is  formed. 

There  is  a  further  question  as  to  whether  trees 
actually  attract  the  clouds  or  not,  and  this  still  waits 
for  a  satisfactory  answer ;  but  it  is  certainly  the  popular 
opinion  that  they  do,  and  it  is  a  very  common  thing  to 
hear  it  said  that  the  clouds  have  gone  over  to  a  neigh- 
bouring park  or  wood,  when  the  farmer  would  have 
been  better  pleased  that  they  should  water  his  fields. 

As  we  began  by  saying,  the  subject  is  a  difficult  one ; 
but  though  we  may  not  be  able  to  explain  precisely 
the  how,  there  is  no  doubt  at  all  as  to  the  fact  that  the 
presence  or  absence  of  all  vegetation,  not  of  trees  only 
does  very  greatly  affect  climate,  and  the  climate  in  its 
turn  affects  vegetation. 

For  instance,  Tacitus,  the  Latin  historian,  writing 
some  eighteen  hundred  years  ago,  mentions  that  not 
even  a  cherry  would  ripen  on  the  banks  of  the  Rhine ; 
and  he  certainly  would  not  have  believed  that  in  cen- 
turies to  come  the  same  region  would  have  become 
warm  enough  to  be  famous  for  its  vineyards.  But 
in  his  day  forests  abounded  all  about  the  river,  and 
it  is  the  removal,  or  great  diminution,  of  these  which 


Ii8  Deserts 

has  raised  the  temperature.  A  similar,  but  in  this  case 
disastrous,  result  has  been  produced  on  the  southern 
slope  of  the  Pyrenees,  where  what  once  were  wide 
fertile  tracts,  covered  with  vegetation,  have  been  turned 
into  wastes  by  the  destruction  of  the  forests  too  reck- 
lessly carried  out. 

Wooded  countries  certainly  seem  on  the  whole  to 
receive  most  rain ;  and  the  clearing  away  of  any  kind 
of  vegetation,  be  it  herbage,  brushwood,  or  forest-trees, 
may  be,  and  often  has  been,  attended  by  evil  conse- 
quences. For  vegetation  protects  the  soil  from 
evaporation,  enabling  it  at  least  to  keep  what  water 
it  receives,  and,  as  this  accumulates,  springs,  or 
reservoirs,  are  formed,  from  which  the  plants  in  their 
turn  may  derive  supplies  when  rain  fails  or  is 
insufficient. 

Then  again,  vegetation  preserves  the  soil  from  the 
assaults  of  wind  and  rain,  a  matter  of  no  small  im- 
portance, especially  in  mountain  regions,  for,  as  we 
have  already  seen,  the  earth  on  the  slopes  may  be 
clean  washed  or  blown  away,  and  the  fertility  of  cen- 
turies may  be  thus  destroyed. 

But  even  this  is  not  all.  The  soil  gone,  what 
remains  ? 

Bare  rock  or  subsoil,  which  is  dried  and  heated  by 
the  sun,  growing  drier  and  therefore  hotter,  till  it  is 
quite  parched.  But  a  dry,  hot  surface  heats  and  dries 
the  air  above  it,  for  hot  air,  being  lighter  than  cold, 
rises. 

From  a  wide  expanse  of  dry  hot  sand,  such  as  that 
of  the  Sahara,  therefore,  there  must  be  a  constant 
upward  current  of  hot  air,  and  this,  again,  must  act 
like  a  furnace  upon  any  moist  current  with  which  it 


Deserts  119 

comes  in  contact.  The  moisture  has  no  chance  of 
condensing  into  a  cloud,  or  rain,  as  it  might  if  it 
met  with  cool  air,  but  is  dispersed — drunk  up  and 
evaporated  by  the  hot,  thirsty  air  from  below.  No 
wonder,  therefore,  that  the  Sahara  is  a  rainless  region. 

The  island  of  St.  Helena,  again,  is  a  notable  instance 
of  what  man  can  do  in  the  way  of  reducing  a  luxuriant 
garden  to  a  barren  waste,  simply  by  his  ignorant  or 
reckless  destruction  of  its  natural  vegetation.  When 
first  discovered,  the  island,  though  very  mountainous 
and  bounded  by  tremendous  precipices  rising  some  two 
or  three  thousand  feet  above  the  sea,  was  very  fertile, 
and  possessed  a  luxuriant  growth  of  forest.  For  it  is 
astonishing  what  a  thin  film  of  soil  is  enough  for  seeds 
to  sprout  in,  if  only  it  be  moist ;  and  it  is  astonishing, 
too,  how  little  soil  will  suffice  even  for  hardy  evergreens, 
birches,  and  other  small  trees,  whose  roots  often  grow 
in  immediate  contact  with  the  rock.  But  one  thing  is 
absolutely  necessary.  If  the  soil  be  shallow,  moisture 
must  be  abundant. 

The  soil  of  St.  Helena  was  rich,  being  formed  by  the 
slow  decay  of  volcanic  rocks,  but  it  was  not  deep,  and 
was  only  kept  in  place  by  the  roots  which  held  it  fast. 
The  Portuguese  brought  goats  to  the  island,  and  by 
these  destructive  animals  the  luxuriant  vegetation  was 
in  great  part  destroyed,  for  they  multiplied  by 
thousands.  There  was  a  wanton  waste  of  wood,  too, 
on  the  part  of  the  human  inhabitants,  though  some 
were  far-sighted  enough  to  predict  that  the  island 
would  be  ruined  when  the  '  Great  Wood '  was 
destroyed.  And  so,  sure  enough,  it  was. 

Gradually  the  soil  became  more  and  more  exposed, 
and  whenever  this  was  the  case,  it  was  washed  away 


I2O  Deserts 

by  the  violent  rains,  leaving  bare  rock  and  utter  barren- 
ness behind.  Still  the  destruction  was  allowed  to  go 
on,  until,  as  the  timber  rapidly  vanished,  not  only  did 
the  soil  follow,  but  the  rain  deserted  it  also,  and  the 
Governor,  taking  alarm,  reported  that  the  island, 
hitherto  abundantly  watered,  was  beginning  to  suffer 
from  drought. 

But  the  authorities — the  island  was  then  in  the 
hands  of  the  Hon.  E.  I.  C. — were  not  to  be  persuaded 
that  there  was  any  connection  between  the  loss  of 
trees  and  the  want  of  rain,  and  returned  for  answer 
that  the  goats  were  more  valuable  than  the  ebony- 
trees,  and  were  not  to  be  destroyed.  So  the  goats 
stayed,  and  the  ebony-trees  went ;  and  the  general 
aspect  of  St.  Helena  became  that  of  a  dreary  rocky 
desert. 

On  the  other  hand,  a  change  greatly  for  the  better 
has  taken  place  in  the  region  round  about  the  Suez 
Canal.  Here  there  was  formerly  hardly  a  blade  of 
grass  to  be  seen,  and  the  land  was  a  desert.  But  the 
cutting  of  the  canal  has  brought  water  into  the  midst 
of  the  parched  land  ;  this  soaks  through  the  sandy 
soil,  and  everywhere  herbage  is  springing  up  along  the 
banks.  Rain  is  still  rare,  but  the  air  is  moister;  for 
the  blazing  sun  draws  up  from  the  canal  large  volumes 
of  water,  which,  though  it  is  only  invisible  vapour  by 
day,  is  chilled  and  condensed  into  water  again  by  the 
lower  temperature  of  the  night,  and  falls  upon  the 
thirsty  land  as  a  heavy,  refreshing  dew. 

But  the  very  fact  that  it  is  a  sandy  district  is  in  its 
favour  in  one  way,  for  water  soaks  easily  through  it, 
and  is  thus  brought  to  the  roots  of  all  plants  growing 
Within  reach. 


Deserts  121 

Then,  again,  in  the  Delta  of  Egypt  there  is  much 
more  cultivation  than  there  was  some  years  back. 
There  are  more  cornfields,  more  pastures,  and  even 
little  forests  are  springing  up,  so  that  its  general  aspect 
is  quite  altered,  and  this  change  is  accompanied  by  a 
change  for  the  better  in  the  climate  also.  Alexandria 
has  rain,  even  to  excess  ;  and  Cairo,  which  used  to 
have  at  most  five  or  six  light  showers  a  year,  now  has 
three  or  four  times  as  much.  The  increase  in  the 
rainfall  seems  to  be  distinctly  traceable  t©  the  increase 
in  the  amount  of  vegetation. 

So  impressed  are  the  Americans  of  the  West  with 
the  connection  between  want  of  trees  and  want  of  rain, 
that  they  now  set  apart  a  day  in  each  year,  which  they 
call  '  Arbor-day/  and  dedicate  to  the  planting  of  trees. 
Before  this  idea  was  started  there  had  been  such  reck- 
less cutting  of  wood  in  the  mountains  and  timber 
regions  as  to  cause  quite  a  dearth  even  of  fire-wood, 
especially  in  what  is  called  the  '  arid-region  '  of  the 
Western  States.  Now,  however,  more  than  six  million 
trees  are  said  to  be  growing  on  formerly  barren  lands, 
and  Kansas  alone  has  250,000  acres  of  artificial  forest 
growing  up — a  change  which  it  is  expected  will  so 
benefit  the  whole  region  that  it  will  cease  to  be  arid. 

In  this  land  we  have  little  idea  of  the  magic  change 
produced  in  the  appearance  of  the  landscape  by  rain 
falling  upon  the  hot,  parched  surface  in  southern  lati- 
tudes. There,  growth  is  so  rapid  that,  in  Ceylon  for 
instance,  a  green  hue  begins  to  colour  the  saturated 
ground  after  a  single  day's  rain,  almost  between  dawn 
and  sunset,  where  all  before  was  dreary  brown. 

But  the  change  which  takes  place  in  the  desert  of 
Nubia  is  far  more  wonderful.  During  the  dry  season 


122  Deserts 

not  a  blade  of  even  withered  grass  is  to  be  seen  ;  trees 
and  bushes  have  shed  their  leaves — their  very  bark  is 
cracked  by  the  fierce  heat.  The  Atbara — that  mighty 
tributary  of  the  Nile,  to  which  its  yearly  inundations 
are  due — has  altogether  ceased  to  flow,  and  is  con- 
verted into  a  barren  waste  of  glaring  sand,  four  or  five 
hundred  yards  wide,  interspersed  with  a  few  pools 
here  and  there.  And  yet  the  tremendous  torrents 
which  pour  down  into  it  from  the  Abyssinian  highlands 
have  never  ceased  to  flow ;  but  the  whole  of  their 
waters,  to  the  last  drop,  have  been  evaporated  on  the 
way  by  the  intense  heat,  or  have  been  absorbed  by  the 
desert-sand  which  has  accumulated  in  the  bed  of  the 
river.  Everything  is  parched,  scorched,  gasping;  not 
only  the  sand,  but  the  air  is  burning. 

Such  is  the  state  of  things  towards  the  end  of  June : 
the  Atbara  is  dead  ! 

Then  one  night,  when  everything  is  suffocating, 
there  comes,  suddenly,  without  warning  of  any  kind, 
a  sound  as  of  distant  thunder,  a  continuous  roll  and 
roar,  which  means  that  the  river  has  arrived  ! 

There,  where  there  was  only  sand  the  day  before,  it 
flows  five  hundred  yards  wide,  a  mighty  flood,  and 
already  fifteen  to  twenty  feet  deep ;  for  the  rain  is 
pouring  down  upon  the  great  table-land  of  Abyssinia, 
and  it  will  continue  to  pour  for  two  or  three  months 
to  come. 

And  the  change  in  all  the  bare  and  withered  trees 
and  shrubs,  how  rapid  and  how  marvellous  it  is  !  In 
two  days'  time,  they  show  signs  of  bursting  into  leaf, 
having  previously  looked  as  dead  as  they  do  with  us 
in  winter  ;  and  as  for  the  mimosas  —  their  light, 
feathery  foliage  is  already  beginning  to  afford  shade. 


Deserts  123 

Yet  there  has  not  been  a  drop  of  rain,  or  even  of 
dew.  The  air  no  doubt  is  moister,  for  evaporation 
from  this  wide  expanse  of  water  must  go  on  at  a 
tremendous  rate.  But  at  present  it  is  too  hot  and 
dry  to  part  with  a  single  drop  ;  and  it  is  from  the  soil 
that  the  trees  have  received  their  fresh  supplies,  so 
quickly  does  the  water  soak  through  the  sand.  But 
this  is  not  all  that  they  will  get.  All  nature  seems  to 
expect  a  change,  for  the  wind  is  blowing  from  the 
south,  and  rain  is  surely  coming ! 

The  natives  of  South  Africa  say  that  the  wind 
'  smells  of  green  grass '  when  the  wind  blows  from  a 
quarter  where  rain  has  fallen,  though  this  may  be 
hundreds  of  miles  away ;  and  thousands  of  cattle  will 
start  off  sometimes  and  travel  immense  distances,  in 
the  endeavour  to  reach  the  fresh  pastures  of  which  the 
wind  tells  them.  So  keen  is  the  scent  of  men  and 
animals  in  lands  which  suffer  from  long  drought 


ROOTS 

PLANTS,  as  we  have  seen,  need  a  constant  supply  of 
water  for  transpiration  and  for  growth.  They  cannot, 
as  a  general  rule,  take  this  in  by  their  leaves,  and 
therefore  must  take  it  in  by  their  roots ;  and  without 
water  the  roots  cannot  take  up  and  supply  to  stem, 
branches,  leaves,  flowers,  and  fruit  that  mineral  matter 
without  which  the  plant  cannot  exist. 

Be/ore  examining  the  way  in  which  the  roots  perform 
their  work  of  supplying  all  parts  of  the  plant  with 
liquid  food,  we  must  briefly  consider  where  the  water 
comes  from. 

For  if,  as  has  been  said,  the  ordinary  rainfall  in 
England  for  the  whole  month  of  July  is  about  300 
tons,  and  if  an  acre  of  pasture-grass  transpires  more 
than  3,000  tons  in  the  same  time,  it  is  quite  evident 
that  the  demand  far  exceeds  the  supply  from  the 
clouds.  Moreover,  the  grass  does  not  get  even  the 
full  benefit  of  that  which  does  fall,  for  a  very  large 
proportion  is  either  at  once  evaporated  from  the 
soil,  or  is  drained  away  into  ponds,  lakes,  streams,  or 
rivers. 

Of  the  rain  which  falls  in  England  between  April  i 


Roots  125 

and  October  i,  it  has  been  calculated  that  90  per  cent. 
is  evaporated  from  the  soil  and  returned  to  the  air. 
From  the  air,  however,  the  soil  again  absorbs  it ;  for 
though  leaves  do  not  absorb  moisture  from  the  air, 
the  soil  does. 

We  speak  commonly  of  the  air  as  being  'damp* 
or  '  dry,'  as  the  case  may  be ;  but  in  point  of  fact 
it  is  never  absolutely  dry,  for  nothing  could  live  in 
it  if  it  were.  It  always  contains  some  amount  of 
watery  vapour,  and,  whether  it  be  large  or  small, 
soil  which  has  been  dried  during  the  day  regains  some 
degree  of  moisture  by  night  by  the  simple  process 
of  sucking  it  from  the  air.  The  air  sucks  it  from 
the  soil  by  day,  especially  during  sunshine  or  dry 
wind,  and  the  soil  thus  dried  sucks  it  back  again  at 
night. 

Some  soils  suck  much  more  moisture  from  the 
air  than  others,  and  some  are  also  able  to  keep  it 
much  longer  than  others.  We  all  know  that  a  sandy 
soil,  for  instance,  is  a  dry  soil :  it  takes  some  time 
to  grow  really  damp,  and  it  dries  again  very  quickly. 
Indeed,  pure  quartz-sand  seems  as  if  it  could  not  be 
moistened  by  anything  short  of  rain  or  dew,  being  in- 
capable of  sucking  any  moisture  from  the  very  dampest 
air. 

A  chalk  or  limestone  soil,  on  the  other  hand,  acts  like 
a  sponge,  and,  though  it  may  dry  on  the  surface,  keeps 
its  moisture  a  long  time  within.  The  subsoil  of  the 
Kalahari  Desert,  already  mentioned,  is  limestone ;  and 
this  is  probably  one  reason  why  the  grass  there  is  able 
to  remain  green  so  long  without  rain.  Such  water  as 
is  received  is  kept  for  some  time,  stored  up  in  the  sub- 
soil. 


1 26  Roots 

Of  all  kinds  of  soils,  it  is  those  containing  most 
vegetable  matter  which  take  up  most  moisture,  and 
also  remain  damp  the  longest. 

It  is  a  curious  fact,  however,  that  the  soils  which  are 
least  ready  to  part  with  their  moisture  to  the  air  are 
also  those  which  are  least  ready  to  part  with  it  to  the 
roots  of  plants.  There  may  be  actually  more  moisture 
in  vegetable  mould  than  in  sand  ;  but  the  latter,  at  all 
events,  makes  the  plants  welcome  to  what  there  is,  and 
lets  them  have  almost  every  drop ;  while  the  mould 
may  have  more  to  give,  but  also  keeps  back  more.  If 
the  two  contained  an  equal  amount  of  water,  there- 
fore, plants  would  actually  be  better  off  for  moisture 
in  the  sand  than  in  the  mould ;  but  this  is  not  the 
case. 

An  experiment  made  for  the  purpose  of  trying 
different  soils  with  regard  to  their  readiness  to  give 
up  their  moisture  to  the  roots  of  plants  gave  some 
very  interesting  results :  the  soils  chosen  were  three 
— i,  loam ;  2,  a  mixture  of  vegetable  mould  and 
sand ;  and  3,  coarse  sand  alone ;  the  loam  held  two 
and  a  half  times  as  much .  moisture  as  the  sand,  and 
the  sand  and  mould  mixed  held  more  than  twice  as 
much. 

In  these  three  soils  were  placed  some  tobacco  plants, 
which  are  very  thirsty  and  very  watery — four-fifths 
water,  indeed.  Their  broad,  tender  leaves  begin  to 
droop  as  soon  as  gathered  owing  to  their  rapid  tran- 
spiration. The  sand  gave  up  the  whole  of  the  water 
it  contained  with  the  exception  of  one  and  a  half  per 
cent.,  and  it  was  not  until  it  had  reached  this  dry  state 
that  the  tobacco  planted  in  it  flagged  ;  the  other  plants 
flagged  when  the  loam  still  contained  eight  per  cent., 


Roots  127 

and  the  vegetable   mould  and   sand  a  fraction   over 
twelve  and  a  quarter  per  cent. 

The  supply  contained  in  the  sand  was  exhausted 
first,  of  course,  because  it  contained  so  much  less  to 
start  with ;  but,  though  the  other  soils  were  not  nearly 
as  dry,  the  plants  flagged  because  they  could  not  get 
hold  of  the  water  which  they  still  contained. 

Some  plants,  such  as  rice,  grow  equally  well  in  soil 
or  water,  but  most  plants  are  injured  by  having  their 
roots  kept  in  water  for  any  length  of  time,  and  are,  as 
a  rule,  in  better  health  when  allowed  to  take  up  the 
moisture  they  need  from  that  which  is  contained, 
invisibly/  in  the  pores  of  the  soil,  when  it  does  not  look 
actually  wet  at  all,  and  no  moisture  could  be  squeezed 
out  of  it. 

But  our  main  point  now  is  to  show  that  soil  may, 
and  does,  become  damp  without  rain.  It  may  be  dried 
by  sun  and  wind  by  day,  but  it  makes  up  for  this  by 
drawing  moisture  from  the  air  by  night,  and  it  is  this, 
partly,  which  enables  plants  at  least  to  live  through  a 
time  of  drought,  though  their  very  stunted  growth 
shows  that  the  supply  has  been  insufficient  for  their 
needs. 

The  moisture  which  the  soil  thus  draws  from  the  air 
does  not  remain  on  the  surface,  but,  like  the  rain  and 
dew,  sinks  into  the  ground,  penetrating  deeper  and 
deeper,  and  moistening  the  soil  until  it  is  used  up,  or 
stopped  by  meeting  either  with  damp  soil,  or  with  soil  or 
rock  through  which  it  cannot  pass.  Rain  falling  upon  a 
porous  soil,  such  as  sand,  or  even  soil  containing  much 
sand,  passes  quickly  through  it  until  it  meets  with  a 
bed  of  stiff  clay  or  rock,  which  prevents  its  going 
further ;  and  then  what  is  left,  over  and  above  what  the 


128  Roots 

soil  has  taken  up,  accumulates,  and  may  in  time  form  a 
spring,  or  even  a  sheet  of  water.  In  some  places  there 
are  known  to  be  very  extensive  underground  lakes,  and 
these  must  do  much  to  keep  the  soil  above  them  moist 
in  the  absence  of  rain.  The  springs,  or  underground 
streams,  too,  do  the  same,  and  in  some  cases  they  flow 
such  long  distances  that  it  seems  not  unlikely  the 
Kalahari  Desert  may  have  some  such  subterranean 
supply  of  water,  which  enables  the  plants  to  live 
through  the  long  terrible  drought. 

But,  it  may  be  asked,  what  is  the  use  to  the  plants 
of  water  so  far  beneath  as  to  be  quite  beyond  the  reach 
of  their  roots  ?  The  answer  to  which  is  that  it  does 
not  remain  beyond  their  reach,  but  is  brought  up  to 
them. 

The  water  in  the  soil,  visible  or  invisible,  is  like  a 
stream  which  is  never  at  rest ;  it  is  in  constant  motion, 
always  either  rising  or  sinking  according  as  the  surface 
of  the  soil  is  damp  or  dry. 

When  the  surface  is  wet  from  rain,  the  rain  goes 
on  sinking  down  and  down  till  it  is  either  absorbed 
by  the  soil  through  which  it  passes,  or  accumulates 
at  some  greater  or  less  depth  below.  But  when  the 
sun  shines  out  again,  or  a  dry  wind  blows,  the 
moisture  of  the  surface  is  evaporated,  the  upper  soil 
grows  dry  again,  and,  the  moment  it  is  drier  than  the 
soil  below,  the  damp  soil  begins  to  give  up  its  moisture 
to  this  drier  bed  immediately  above  it.  Thus  the 
stream  of  moisture  at  once  begins  to  ascend,  and  will 
continue  to  ascend  until  the  surface  is  wetted  again ; 
it  moves,  in  fact,  either  up  or  down,  to  the  drier  parts 
of  the  soil,  whichever  these  may  be,  the  movement 
being  exactly  like  that  of  the  oil  in  the  wick  of  a  lamp ; 


Roots  129 

as  fast  as  the  oil  is  consumed,  more  rises  to  take  its 
place. 

In  time  of  drought  the  soil  may  appear  quite  dry 
even  to  some  depth,  but,  as  we  have  seen  in  the  case 
of  the  tobacco  planted  in  sand,  plants  can  continue  to 
draw  moisture  from  the  soil  long  after  all  trace  of 
moisture  has  vanished,  so  far  as  can  be  seen.  To  find 
it  at  all  we  should  have  to  dry  the  soil  by  artificial 
heat ;  but  it  is  there,  and  the  plant  manages  to  draw  it 
out. 

In  very  long  droughts,  even  the  springs  near  the 
surface  may  fail,  all  their  water  being  drawn  away 
from  them  by  degrees ;  but  still,  at  a  greater  or  less 
depth,  some  water  there  is,  for  the  deeper  wells  do 
not  fail  though  the  shallow  ones  may;  and,  unless 
this  water  be  buried  under  some  bed  through  which 
it  cannot  pass,  it  will  continue  to  rise  to  the  sur- 
face. 

The  water  which  plants  need,  therefore,  for  growth, 
and  to  supply  the  small  loss  by  evaporation  and  the 
large  loss  by  transpiration,  comes  to  them  from  rain  and 
dew ;  it  is  also  very  largely  absorbed  from  the  air  by 
the  soil ;  and  the  large  stores  accumulated  in  the 
ground  are  also  drawn  upwards  as  they  are  needed — 
chiefly,  of  course,  during  the  spring  and  summer.  It\ 
autumn,  when  growth  ceases,  transpiration  is  less ;  in 
winter,  when  the  trees  are  bare,  there  is  next  to  none, 
so  that  they  have  little  need  of  water.  In  spring  and 
summer,  on  the  other  hand,  they  need  much,  and 
receive  it,  in  part,  from  the  accumulated  stores  of  the 
other  months. 

All  the  water  which  plants  transpire — in  many  cases 
a  very  large  quantity,  as  we  have  seen — is  taken  up  by 

9 


T  50  Roots 

their  roots,  and  their  roots  alone.  And  these  roots  we 
must  now  look  at  a  little  more  closely. 

A  root  is  a  very  wonderful  organ,  much  more  won- 
derful than  a  passing  glance  would  lead  one  to  suppose. 
A.nd,  indeed,  the  most  important  parts  cannot  even  be 
seen,  without  careful  examination. 

The  root  serves  two  purposes  :  it  keeps  the  plant  in 
one  place,  enabling  it  to  stand  against  the  wind  ;  and 
it  collects  from  the  soil  food  and  water  which  the 
plant  can  obtain  in  no  other  way,  and  without  which  it 
can  neither  grow  nor  exist. 

Some  plants  have  a  single  fleshy  root,  like  that  of  a 
carrot,  which  descends  straight  into  the  earth,  and  has 
no  branches,  but  only  a  few  fibres  growing  from  it.  A 
carrot  needs  a  good  pull  to  uproot  it ;  but  an  onion  is 
easily  lifted  from  the  earth,  as  its  roots  are  only  fibres 
growing  from  the  base  of  the  bulb ;  while  a  dock  may 
resist  the  full  strength  of  a  man. 

Water-plants  have  few  roots,  as  their  food  comes  to 
them  already  prepared,  without  their  having  to  search 
for  it ;  bog-plants  have  more  roots,  as  they  have  more 
work  to  do ;  and  land-plants  have  most  of  all,  as  their 
roots  frequently  have  to  explore  the  earth  for  a  con- 
siderable distance  in  search  of  food. 

In  a  fertile  soil,  where  there  is  plenty  of  food,  roots 
are  generally  short  and  much  branched.  They  branch 
out,  in  fact,  where  the  food  is  to  be  found.  But  in  a 
poor  soil  they  have  to  go  further  to  find  what  they  need, 
and  are  usually  long  and  slender. 

But  the  mere  mention  of  so  many  feet  gives  no  idea 
at  all  of  the  real  length  of  a  plant's  roots  ;  for  besides 
the  long  main  roots,  there  are  rootlets  innumerable 
branching  from  them,  and  these  rootlets,  though  they 


Roots  131 

may  be  mere  threads  themselves,  are  covered  with 
millions  of  hairs,  generally  so  minute  as  to  be  hardly 
visible  without  the  help  of  a  microscope. 

But  here  again,  as  we  have  seen  in  various  ways 
before,  it  is  the  small,  insignificant  workers  which  are 
of  the  most  importance.  It  is  through  the  younger, 
threadlike  rootlets,  and  through  these  millions  of 
minute  hairs,  that  food  is  chiefly  taken  up ;  and  this  is 
why,  in  moving  a  plant,  the  gardener  is  careful  to  keep 
a  ball  of  earth  round  its  roots,  that  the  small,  deli- 
cate rootlets  may  not  be  injured,  and  its  food-supply 
lessened. 

The  root-hairs  are  being  constantly  produced  in 
fresh  millions,  for  each  individual  lasts  but  a  few  days. 

It  is  difficult  in  any  degree  to  realize  what  length  of 
root  a  plant  possesses,  for  to  do  this  one  must  measure 
not  only  the  main  root,  or  roots,  but  the  branches, 
rootlets  and  fibres  as  well ;  and  even  then,  the  fringe 
of  hairs  will  have  to  be  left  altogether  unreckoned. 

An  oat  or  barley  plant,  for  instance,  has  roots 
several  feet  long ;  but  when  we  say  several  feet,  we 
merely  mean  that  they  stretch  several  feet  down- 
wards through  the  soil.  Their  real  length,  if  the 
many  roots  are  measured  end  to  end,  branches  and 
all,  is  a  very  different  matter.  A  barley  -  plant 
grown  in  a  very  small  quantity  of  rich  porous  soil, 
was  found  to  have  a  total  length  of  root  of  128 
feet !  This  measurement  included  the  fibres,  but  not 
the  hairs.  In  loose  soil,  such  as  this,  roots  can  make 
their  way  easily;  but  in  closet  soil,  growth  is  more 
difficult,  and  so  slower,  and  a  plant  grown  in  soil  of 
the  latter  sort  had  roots  only  80  feet  long.  Only  80 
feet ;  but  both  the  80  feet  and  the  128  feet  were  packed 


132  Roots 

into  the  fortieth  part  of  a  cubic  foot  of  soil,  a  quantity 
which  would  be  contained  in  a  box  between  three  and 
four  inches  square  and  equally  deep. 

Of  course,  if  these  roots  had  had  their  liberty  they 
would  have  been  much  less  branched,  and  would  have 
spread  much  further.  They  would,  so  to  say,  have 
gone  much  further  ahead,  without  running  up  so  many 
by-paths.  But  being  prisoners,  they  had  to  make 
the  most  of  what  they  had,  and  so  explored  most 
thoroughly  the  small  space  at  their  command.  Every- 
one knows  what  a  mat  of  roots  and  fibres  there  will  be 
when  a  plant  is  taken  out  of  a  pot  too  small  for  it ;  such 
a  mat  that  the  earth  is  often  completely  enveloped. 

Now,  of  course,  it  is  not  natural  for  a  plant  to  grow 
in  a  confined  space,  with  its  roots  crowded  together  in 
this  way,  and  when  left  to  grow  as  it  likes,  in  the  open 
ground,  its  roots  often  roam  to  great  distances,  and 
therefore  require  much  more  soil  than  they  make  use 
of  as  food.  The  poorer  the  soil  the  farther  the  roots 
spread  in  their  endeavour  to  find  nourishment,  and  a 
maize-plant  in  sandy  soil  will  send  its  roots  out  a  dis- 
tance of  ten  or  fifteen  feet. 

It  is  supposed  that  only  a  very  small  portion,  perhaps 
a  hundredth  part,  of  the  soil  helps  to  feed  the  plants 
growing  in  it.  And  this  is  probable  enough  when  we 
consider  it ;  for  the  soil,  however  fine,  still  consists  of 
solid  particles,  which  the  roots  cannot  swallow ;  and 
though  it  is  being  constantly  dissolved  by  water  and 
gases,  the  process  is  a  slow  one.  Where  the  soil  is 
coarse  the  process  is  slower  still.  For,  as  a  lump  of 
sugar  takes  much  longer  to  dissolve  than  the  same 
quantity  of  sugar  when  reduced  to  powder,  just  so  it 
is  with  the  soil ;  when  it  is  fine  the  water  has  a  very 


Roots  133 

much  larger  surface  to  act  upon,  and  can  act  more 
quickly.  And  this  is  one  reason  why  finely-ground 
soils  are  so  generally  fertile. 

But  this  is  not  the  only  reason ;  for,  besides  drink- 
ing in  the  moisture  of  the  soil,  with  whatever  may  be 
dissolved  in  it,  the  roots  do  much  dissolving  on  their 
own  account.  And  it  is  for  this  purpose,  apparently, 
that  all,  down  to  the  smallest  fibre,  and  even  hair,  are 
more  or  less  acid. 

What  food  comes  to  them  ready  dissolved  may  be 
brought  from  a  distance  from  the  soil  above  or  below 
the  roots,  but  it  is  brought.  The  particles  of  soil,  on 
the  other  hand,  do  not  move,  and  the  roots  must  go  to 
them,  and  actually  touch  them,  and  that  very  closely, 
for  the  acid  to  be  able  to  act  upon  them.  A  rich 
morsel  which  is  a  foot,  or  even  an  inch  or  a  half-inch 
away,  is  of  no  use,  except  so  far  as  it  may  be  dissolved 
by  water.  The  roots  can  do  nothing  with  it  unless 
some  part  of  them,  fibres  or  hairs,  are  near  enough  to 
get  hold  of  it  and  press  close  to  it,  as  the  lichen  adheres 
to  the  rock. 

And  it  is  this  which  makes  it  so  important  that  a 
soil  should  be  not  only  finely  ground,  but  well  mixed, 
so  that  all  the  ingredients  may  be  within  reach  of  the 
roots  of  each  plant. 

Most  soils  distinguished  for  their  fertility  contain  a 
large  proportion  of  fine  matter,  and  to  this  is  largely 
due  the  extraordinary  productiveness  of  some  of  the 
lands  of  Ohio,  which  have  borne  heavy  crops  of  wheat 
and  maize  for  sixty  years  in  succession.  A  consider- 
able part  of  the  soil  here  consists  of  particles  which 
measure  from  the  five-hundredth  to  the  thousandth 
part  of  an  inch  across.  The  same  thing  is  to  be 


134  Roots 

observed  in  the  Black  earth  of  Russia,  and  again  in 
the  mud  brought  down  by  the  Nile  and  other  rivers : 
all  are  distinguished  for  the  fineness  of  their  particles 
and  their  thorough  mixture. 

Why  is  it  that  a  block  of  granite  is  able  to  support 
only  a  few  lichens  and  mosses  ?  Chiefly  because  it  is 
a  block,  into  which  roots  cannot  penetrate.  It  would 
not  make  a  really  fertile  soil  even  if  it  were  crushed 
into  coarse  gravel,  but  it  would  grow  more  than  it  does 
now ;  and  if  it  were  ground  to  fine  powder  and  kept 
well  watered  it  would  grow  even  corn — not  perhaps 
good  crops,  though  even  granites  differ  in  fertility,  but 
still  corn — whereas  not  a  stalk  can  spring  up  while  the 
granite  remains  a  block,  no  matter  how  diligently  it  be 
watered. 

By  way  of  testing  this  point,  an  experiment  was 
made  with  some  barley  sown  in  a  soil  consisting  ot 
pure  felspar.  Felspar  is  that  one  of  the  three  minerals 
of  which  granite  is  composed,  which,  when  finely 
powdered  and  washed  away,  forms  beds  of  clay.  In 
this  case  it  was  first  only  coarsely  powdered,  and  the 
barley  grew  to  a  height  of  fifteen  inches;  moreover, 
the  ears  formed,  one  ear  ripened,  and  two  seeds  were 
perfected.  In  the  second  instance  the  felspar  was  finely 
powdered,  and  the  stalks  were  very  much  stronger. 
One  grew  to  a  height  of  twenty  inches,  and  perfected 
four  seeds. 

Felspar  alone,  though  a  compound  of  several 
elements,  could  not  in  any  case  produce  a  good  crop; 
for  the  stiffest  clay  soils  under  cultivation  have  been 
not  only  well  ground,  whether  by  ice  or  water,  but 
also  mixed  besides,  and  contain  sand  and  other  in- 
gredients, 


Roots  135 

It  is,  of  course,  possible  for  the  soil  particles  to  be 
too  fine,  as  they  are  in  pure  clay,  which  is  so  close  in 
texture  as  to  exclude  what  is  as  necessary  to  the  plant 
as  food  and  water,  namely,  air.  A  plant's  roots  need 
air  as  much  as  any  other  part  of  it,  for  they  are  con- 
stantly taking  up  oxygen,  and  hence  all  specially  fertile 
soils  contain  a  large  proportion  of  sand,  which  makes 
them  light  and  porous ;  for,  though  fine,  it  is  not  nearly 
as  fine  as  the  particles  composing  the  clay,  and  does 
not  turn  into  a  stiff  paste  when  mixed  with  water. 

In  a  stiff,  heavy  soil  roots  make  their  way  with  less 
ease  and  with  less  rapidity  than  in  a  light,  loamy  one 
containing  a  large  proportion  of  sand,  and  therefore 
they  must  needs  collect  food  less  rapidly.  Moreover, 
both  air  and  water  penetrate  a  heavy  soil  less  easily 
than  they  do  a  light  one,  and  hence  not  only  is  the  air 
which  the  roots  need  less  able  to  reach  them,  but  less 
water  can  enter  also,  and  consequently  less  soil  is  dis- 
solved and  made  ready  for  their  use.  The  '  loamy 
soil '  which  a  farmer  loves  contains  from  forty  to 
seventy  per  cent,  of  sand. 

Here,  again,  we  see  the  great  usefulness  of  earth- 
worms. In  sand  they,  like  the  roots,  can  make  their 
way  so  easily  that  they  have  little  need  to  remove  the 
soil  by  swallowing  it,  the  only  means  at  their  disposal. 
But  in  a  stiffer  soil  they  are  obliged  to  do  this,  and 
thus  they  let  in  both  air  and  water,  to  the  great 
advantage  of  the  plants,  while  they  also  spare  the  roots 
much  labour  by  preparing  for  them  airy  passages, 
down  which  they  can  run  with  ease. 

But  though  roots  take  advantage  of  these  ready- 
made  channels,  and  are  evidently  all  the  better  for 
them,  they  do  not  let  go  their  hold  on  the  soil, 


136  Roots 

but  keep  a  close  grasp  of  it,  lining  the  worm- 
burrows  with  thread-like  fibres,  which  cling  fast  to 
the  sides. 

Roots  corning  in  contact  with  a  piece  of  limestone 
will  leave  upon  it  a  perfect  impression  of  themselves, 
even  to  the  hairs  with  which  they  are  fringed,  showing 
how,  like  the  lichens,  they  have  eaten  their  way  into 
the  solid  substance. 

How  do  they  do  it  ?  We  can  hardly  do  more  than 
conjecture ;  but  it  seems  probable  that  the  acid  in  the 
roots  acts  much  as  acid  contained  in  a  bladder  would. 
If  a  glass  tube  is  filled  with  water  made  slightly  acid 
with  vinegar,  and  then  covered  with  a  piece  of 
moistened  bladder  strained  tightly  over  the  mouth, 
and  in  contact  with  the  liquid,  this  will  represent  the 
root,  though  the  resemblance  would,  of  course,  be 
closer  if  the  tube  itself  were  of  bladder.  This,  how- 
ever, seems  to  be  the  only  practicable  way  of  trying 
the  experiment.  The  acid  is  very  weak,  as  the  acid  in 
the  roots  is  weak  ;  but  if  salts,  such  as  phosphate  of 
lime,  and  others  found  in  the  soil,  are  now  strewn 
upon  the  bladder,  they  will  in  a  short  time  begin  to 
pass  through  it  into  the  tube,  being  dissolved  by  the 
weak  acid  in  its  pores. 

The  acid  in  the  roots  acts,  it  is  supposed,  in  a 
similar  way,  and  thus  the  dissolved  minerals  are 
sucked  in.  But,  as  before  said,  living  things  have 
more  power  than  dead  ones ;  so  it  may  well  be  that 
roots,  like  lichens,  dissolve  more  than  the  weak  acid 
alone  would  do. 

The  roots  take  up  what  they  themselves  dissolve 
from  the  particles  of  soil  immediately  surrounding  and 
closely  touching  them,  and  also  what  the  water  in  the 


Roots  137 

soil  has  dissolved  for  them,  with  the  help  of  carbon- 
dioxide  and  other  gases. 

The  water  thus  taken  up — for  what  is  dissolved  by 
the  roots  and  what  is  dissolved  by  water  and  gas  are 
taken  up  together — the  water  thus  taken  up  is  a  very 
weak  solution  of  various  salts — phosphates,  and  others 
— so  weak  that  it  may  fairly  be  compared  with  ordinary 
drinking-water. 

No  water  in  nature  is  or  can  be  perfectly  pure,  as 
has  been  said,  because  it  is  constantly  dissolving  some- 
thing wherever  it  goes.  And  though,  even  with  what 
the  roots  have  dissolved,  the  solution  is  still  so  weak  as 
to  pass  for  ordinary  water,  yet  it  must  be  borne  in 
mind  that  the  roots  are  constantly  sucking  it  in,  and 
that  the  leaves  are  as  constantly  returning  the  water 
to  the  air — only  the  water,  however.  The  salts  remain 
behind  and  accumulate  day  by  day. 

The  same  sort  of  thing  on  a  vast  scale  goes  on  with 
the  rivers  and  the  ocean.  River- water  is  generally 
tasteless,  though  it,  too,  contains  various  salts  dissolved 
in  it.  This  small  proportion  of  salts  is,  however,  being 
constantly  poured  into  the  ocean,  while  the  sun  is 
constantly  taking  away  by  evaporation  almost  pure 
water.  The  salts,  therefore,  accumulate,  and  sea- 
water  is  salt  and  bitter  in  consequence. 

The  salts  left  in  a  plant  do  not  usually  make  it  salt 
or  bitter,  because  the  quantity  is  altogether  extremely 
minute  in  proportion  to  the  plant's  size ;  and  as  they 
are  distributed  through  the  whole  of  its  substance, 
there  is  a  continual  demand  for  them  while  the  plant 
is  growing  or  putting  forth  fresh  leaves. 

But  if  a  plant  is  stunted  by  drought  it  may  become 
actually  bitter  A  cabbage,  for  instance,  which  has 


Roots 

not  reached  perhaps  a  quarter  its  proper  size  for  want 
of  water,  will  be  quite  bitter;  and  the  reason  seems  to  be 
that  the  salts,  which  would  have  been  enough  for  a  large 
cabbage,  are  compressed  into  a  very  small  one.  Or,  in 
other  words,  the  roots  have  not  been  able  to  find 
enough  water  to  dilute  the  food  which  they  have 
gathered,  as  well  as  to  keep  pace  with  the  transpiration 
of  the  leaves,  and  to  allow  of  their  proper  growth. 


XL 

FOOD   FROM   THE   SOIL 

IT  is  but  a  very  small  part  of  their  food  after  all  which 
plants,  generally  speaking,  draw  from  the  mineral 
matter  of  the  soil  in  which  they  grow ;  and  yet  this 
small  quantity  is  not  merely  important,  but  absolutely 
necessary.  It  is  dissolved  by  water  and  gases,  and  by 
the  action  of  the  plant  itself,  and  is  then  taken  up  by 
the  roots,  especially  the  younger,  finer  roots,  and  root- 
hairs,  by  which  it  is  passed  on  to  the  stem,  and  so  is 
conveyed  to  every  part,  not  only  to  branches,  leaves, 
and  buds,  but  also  to  flowers  and  fruit.  Every  part 
of  a  plant  needs  some  amount  of  mineral  matter,  and 
the  plant  cannot  obtain  it  without  water,  for  whether 
dissolved  by  the  plant's  roots  or  otherwise,  it  is  in  each 
case  taken  up  in  a  very  diluted  condition  ;  so  diluted, 
indeed,  that  the  water  containing  it  is  hardly  to  be  dis- 
tinguished from  ordinary  drinking-water. 

The  plant  could  not  be  sufficiently  nourished  by 
these  very  weak  dilutions,  especially  while  it  is  growing, 
but  for  the  fact  that  it  is  constantly  receiving  them. 

Perhaps  one  of  the  most  striking  examples  of  the  way 
in  which  plants  are  fed  by  this  very  weak  food  is  to  be 
found  among  the  sea-weeds.  Many  sea-weeds  contain 


140  Food  from  the  Soil 

large  quantities  of  iodine,  which,  like  the  rest  of  their 
food,  they  draw  from  the  sea.  With  the  smell  of 
iodine  we  are  all  no  doubt  familiar ;  but  if  we  mix  one 
part  of  iodine  with  300,000  parts  of  water  we  entirely 
lose  it.  That  is  to  say,  no  one  of  our  senses  is  keen 
enough  to  detect  it.  We  can  neither  see,  nor  taste, 
nor  smell  it.  But  of  course  it  is  there,  and  we  can 
find  it  again  by  adding  starch,  which  is  turned  to  a 
brilliant  blue  by  coming  in  contact  with  even  this 
minute  quantity. 

But  the  iodine  contained  in  sea-water  is  less  even 
than  this — it  is  less  even  than  the  hundredth  part  of 
this  infinitesimal  amount.  And  yet  the  sea-weed 
manages  to  extract  it.  And  although  plants  take  their 
mineral  food  in  such  weak  dilutions  that  we  cannot 
detect  its  presence  either  by  taste  or  smell,  and  might 
be  inclined  to  think  that  it  can  matter  very  little  what 
it  is,  yet  they  are  discriminating ;  and  their  roots  have 
to  some  extent  the  power  of  choosing  what  they  will, 
or  will  not,  take  up. 

This  is  evident  from  the  fact  that  plants  growing 
side  by  side  will  take  up  different  food,  or  take  it  in 
very  different  proportions. 

There  is,  for  instance,  the  common  reed  and  the 
common  species  of  moss,  which  both  grow  in  bogs. 
The  soil  is  dissolved  by  water  and  gases  equally  for 
both,  and  both  take  up  a  good  deal  of  dissolved  flint, 
or  silica;  but  the  reed  takes  up  also  a  very  small 
quantity  of  salt,  a  little  more,  but  still  a  very  small 
quantity,  of  iron,  no  soda,  a  little  magnesia,  and  a  great 
deal  of  phosphoric  acid ;  whereas  the  moss,  which  grows 
close  by,  takes  very  little  either  of  phosphoric  acid, 
magnesia  or  salt,  but  some  soda,  and  much  iron 


Food  from  the  Soil  141 

The  same  thing  is  also  true  of  the  farmer's  crops, 
and  it  is  for  this  reason  that  he  varies  them,  not 
growing  the  same  crop  year  after  year,  or  even  two 
years  running,  on  the  same  soil,  lest  it  should  be 
exhausted  and  unable  to  feed  them. 

Corn-crops,  for  instance,  take  up  much  flint,  which 
goes  chiefly  to  give  the  hard,  glossy  coating  to  their 
stems ;  and  they  want  from  a  fifth  to  a  tenth  part  as 
much  potash.  Turnips  and  beet,  on  the  other  hand, 
take  in  little  flint,  but  more  lime  and  potash;  and 
turnips  and  carrots  will  use  up  the  sulphuric  acid; 
while  clovers  want  little  sulphuric  acid,  but  much 
potash,  lime  and  soda. 

All  plants  need  more  or  less  of  several  mineral  sub- 
stances, and  even  when  it  is  Mess,'  they  cannot  do 
without  this  lesser  quantity,  be  it  never  so  small. 
When,  therefore,  we  say  that  corn-crops  take  up  much 
silica  or  flint,  it  is  not  at  all  meant  that  they  do  not 
take  some  proportion  of  lime,  potash,  soda,  sulphur, 
iron  and  phosphoric  acid  as  well;  for  they  use  them 
all,  in  larger  or  smaller  quantities. 

The  amount  taken  up  of  each  varies  in  different 
kinds  of  corn ;  wheat,  oats,  barley,  etc.,  have  all  their 
special  needs,  and  so,  too,  have  different  varieties  of 
the  same  kind  of  corn.  More  than  this,  different  plants 
of  the  same  variety  differ  slightly  in  this  respect,  as 
if  they  had  their  own  individual  preferences ;  but  the 
difference  is  very  slight,  and  in  plants  of  the  same 
species,  the  proportion  always  remains  nearly  the 
same. 

And  this  is  true,  no  matter  where  the  plant  may 
grow.  If  it  grows  at  all,  its  ash — that  is,  the  mineral 
substances  which  it  has  taken  from  the  soil — will  always 


142  Food  from  the  Soil 

be  found  to  be  pretty  nearly  the  same ;  the  proportion 
will  be  the  same,  that  is  to  say,  for  of  course,  in  un- 
favourable soil,  the  plant  may  be  a  dwarf.  Grasses, 
for  instance,  which  are  like  corn  in  taking  in  consider- 
able quantities  of  silica,  will  take  up  just  as  much  of 
this  when  they  grow  on  the  chalk  soil  of  the  downs  as 
when  they  grow  in  a  soil  containing  much  sand.  Yet 
chalk,  pure  chalk,  does  not  contain  a  particle  of  silica. 

As  before  remarked,  however,  such  a  thing  as  a 
perfectly  unmixed  soil  is  hardly  to  be  found  anywhere. 
Even  on  the  mountains  there  is  rarely  less  than  ten 
per  cent,  of  soil  which  has  been  brought  from  else- 
where, either  by  wind  or  water,  or  added  to  it  by 
animals.  So  it  is  on  the  downs,  and  the  grass  finds 
there  what  it  needs. 

It  would  be  rash  to  say  of  any  plant  that  it  will  not 
grow  on  any  soil  until  it  has  been  tried;  but  plants 
certainly  have  their  likes  and  dislikes  in  this  matter, 
though  sometimes  a  good  climate  will  make  up  for 
poor  soil. 

Clover,  for  instance,  loves  lime;  and  cowslips  and 
primroses  are  poor  and  scanty  where  lime  is  deficient, 
and  luxuriant  on  chalk ;  but  the  heather,  in  this  country 
at  all  events,  shuns  lime ;  and  though  it  may  be  found 
growing  close  by  on  a  patch  of  sand,  and  though  its 
seeds  must  be  scattered  all  around,  it  is  not  to  be  found 
on  the  chalk  downs.  Here  and  there  a  stray  plant 
may  be  seen  growing  in  a  mixture  of  sand  and  chalk ; 
but  as  a  rule  it  is  conspicuously  absent  from  chalk 
and  limestone  in  England,  and  in  Wurtemberg  it 
actually  disappears  even  from  sandy  soils,  if  marl 
containing  more  than  a  fifth  part  of  lime  be  added  to 
them.  But  the  same  thing  does  not  hold  good  in 


Food  from  the  Soil  143 

France,  where  heather  is  sometimes  to  be  seen  actually 
thriving  on  a  limy  soil. 

Some  plants  have  such  peculiar  tastes,  or  require- 
ments, in  respect  of  soils,  that  they  must  seldom,  one 
would  think,  be  able  to  gratify  them ;  and  one  almost 
wonders  where  the  seeds  come  from  when  the  oppor- 
tunity for  growing  does  arrive. 

Some,  for  instance,  are  never  to  be  seen  except  after 
forest  -  fires ;  apparently  because  they  require  wood- 
ashes  to  grow  in.  Other  plants  have  similar  likings ; 
and  it  was  observed  that  after  the  fires  of  London  and 
Copenhagen,  plants  of  the  same  kinds  grew  among  the 
ruins  of  both  cities. 

It  is  very  remarkable,  too,  what  slight,  and  even 
imperceptible,  differences  in  the  soil  will  make  very 
great  differences  in  the  crops  grown  upon  them.  This 
is  especially  noticeable  in  the  case  of  vines.  Tokay 
wine,  for  instance,  cannot  be  made  except  from  grapes 
grown  in  the  one  district  from  which  it  takes  its  name. 
The  vines  may  be  grown  elsewhere,  but  the  wine  is 
different.  So,  too,  in  France ;  vineyards  growing  side 
by  side,  and  separated  only  by  a  narrow  footpath, 
having  the  same  aspect,  and  apparently  the  same  soil, 
and  cultivated  in  precisely  the  same  way,  yet  produce 
wine  of  quite  different  qualities  and  very  different 
values. 

Plants  differ,  too,  extremely,  among  other  things,  as 
to  the  quantity  of  salt  which  they  take  up.  To  corn, 
and  most  other  plants,  any  large  quantity  is  absolutely 
fatal.  Some,  however,  take  up  much. 

On  the  west  coast  of  France  grow  various  species  oi 
the  small  plants  called,  from  their  love  of  salt,  salt- 
worts, which  are  interesting  because,  though  they  are 


144  Food  from  the  Soil 

entirely  lost  sight  of  as  one  moves  inland,  and  are  not 
to  be  seen  anywhere,  all  across  Europe,  except  in  the 
neighbourhood  of  salt-springs,  yet  they  do  reappear 
in  some  parts  of  Hungary,  and  in  the  great  plains,  or 
steppes,  of  south-east  Russia,  where  the  soil  contains 
so  much  salt  as  to  be  often  encrusted  with  it  in 
summer. 

Here  these  plants  thrive  as  well  as  on  the  coast,  but 
nothing  else  will  grow,  except  a  few  such  plants  as  are 
nearly  related  to  them ;  and  in  some  places  it  is  the 
custom  to  cut  and  remove  the  whole  crop  of  these 
every  year,  by  way  of  improving  the  soil.  The  plants 
have  some  value  in  themselves,  because  they  yield  soda 
—common  salt  being  a  compound  of  soda ;  but  the 
main  object  in  cutting  them  is  that,  by  this  means,  the 
salt  may  be  gradually  removed  from  the  soil,  so  that 
other  and  more  useful  crops  can  be  grown  in  it. 

And  what  is  true  of  the  saltworts  is  true  of  every 
crop.  That  is  to  say,  every  crop  takes  away  from  the 
soil,  not  one  mineral  substance  only,  but  several,  in 
larger  or  smaller  proportions ;  and  the  soil  is  to  this 
extent  poorer  than  it  was  before.  If  the  crop  is  cut 
and  carried,  nearly  the  whole  of  what  it  has  taken  up 
is  lost  to  the  soil ;  in  the  case  of  turnips  and  other 
root-crops,  the  whole  plant  is  taken  away,  and  the  loss 
is  so  much  the  greater. 

A  meadow  which  is  mown  by  a  machine,  too,  loses 
more  than  one  mown  with  the  scythe,  as  the  machine 
cuts  closer ;  and  horses  are  said  to  take  more  from  a 
meadow  than  either  sheep  or  cows,  for  a  similar  reason, 
because  they  are  closer  feeders.  But  where  a  crop  is 
consumed  by  animals,  it  is  not  all  lost  to  the  soil. 
On  the  contrary,  so  much  is  returned  to  it  in  their 


Food  from  the  Soil  145 

droppings,  and  returned,  too,  with  increased  fertilizing 
powers,  that  the  land  is  actually  benefited,  and  needs 
no  other  manure;  whereas  hay-meadows  cannot  go 
on  bearing  crops  year  after  year  without  being  manured 
or  top-dressed,  to  make  up  for  their  yearly  loss. 

It  is  a  different  matter,  of  course,  where  the  crops 
grown  by  nature  are  concerned  ;  for  these,  being  neither 
machine-mown  nor  scythe-mown,  so  far  from  rendering 
the  soil  poorer,  really  do  much  to  enrich  it. 

Herds  of  wild  cattle  may  eat  off  grass  and  herbage, 
as  they  did  for  ages  before  man  came  and  took  posses- 
sion of  their  grazing  grounds,  but  they  manured  the 
soil  in  return.  And  the  same  is  true,  in  its  degree, 
of  squirrels,  monkeys,  birds,  bats — in  fact,  of  all  the 
grain,  fruit,  and  vegetable  eaters. 

The  same  is  also  true,  though  in  a  different  way,  of 
the  plants  themselves.  If  they  are  left  alone,  they 
return  to  the  soil  all  that  they  have  taken  from  it,  and 
more  besides.  For  they  give  to  it,  also,  that  food 
which  they  draw  from  the  air,  of  which  we  have  yet  to 
speak. 

The  roots  of  a  tree  are  constantly  bringing  up  sup- 
plies from  the  deep  subsoil,  which,  when  the  leaves  fall, 
are  added  to  the  surface-soil ;  and  the  ancient  forests 
of  North  America,  after  flourishing  for  ages,  and  pro- 
ducing enormous  quantities  of  timber,  left  the  soil, 
not  impoverished,  but  so  rich  that  it  was  hardly 
exhausted  by  a  whole  century  of  wasteful  farming. 

The  '  yellow  earth '  of  China,  a  deposit  of  very  great 
extent,  is  believed  to  consist  very  largely  of  the  ashes 
of  plants,  accumulated  during  more  generations  than 
one  can  attempt  to  realize,  for  in  some  parts  it  is  more 
than  1,500  feet  thick* 

10 


146  Food  from  the  Soil 

It  is  the  long-continued  course  of  this  green-manuring 
which  has  so  largely  contributed  to  produce  the  extra- 
ordinary fertility  of  the  '  Black  earth '  of  Russia  and 
the  region  of  Manitoba.  And  so,  too,  with  the  Pampas 
of  South  America,  a  still  more  interesting  example, 
because  the  process  is  going  on  under  our  eyes. 

In  the  winter  Captain  Head  found  the  'thistle'  part 
of  this  region  looking  something  like  a  rough  turnip- 
field  intermixed  with  clover,  so  large  and  luxuriant  were 
the  leaves  of  the  '  thistles' — really  wild  artichokes.  In 
the  spring,  the  'thistle '-leaves  had  spread,  and  had 
overgrown  the  clover,  but  still  had  the  appearance  of  a 
rough  crop  of  turnips.  Less  than  a  month  later,  how- 
ever, they  had  shot  up  in  the  most  surprising  manner, 
and  were  in  full  bloom.  They  were  now  ten  or  eleven, 
feet  high,  and  formed  such  a  close,  impenetrable  barrier 
on  each  side  of  the  track  that  nothing  whatever  could 
be  seen  in  any  direction.  The  growth  was  so  amazingly 
rapid  that  an  army  might  easily  have  been  hemmed  in 
unawares  by  the  thick,  strong  stems. 

Before  the  end  of  the  summer  there  was  another 
change.  The  heads  drooped,  the  leaves  faded,  the 
stems  turned  black  and  rattled  in  the  breeze  until  they 
were  blown  down  by  the  periodical  hurricane,  when 
they  quickly  rotted  away,  and  the  strong  luxuriant 
clover  rushed  up  again. 

The  artichoke,  as  well  as  its  near  relation  the  true 
thistle,  requires  a  rich  soil,  and  would  be  an  exhaust- 
ing crop  if  it  were  cut  and  removed,  because  it  takes 
so  much  food ;  but  as  the  roots  penetrate  to  a  great 
depth,  it  benefits  the  clover,  and  the  clover  in  its  turn 
enriches  the  soil  for  the  thistles. 

Clover  is  found,  indeed,  to  be  such  a  beneficial  crop 


Food  from  the  Soil  147 

that  farmers  in  America  sometimes  grow  it  in  alternate 
rows  with  wheat,  and  this  is  also  the  only  kind  of 
green-manuring  commonly  practised  in  England.  It 
is  in  warm  countries,  where  growth  is  rapid,  that  this 
sort  of  manuring  is  chiefly  useful ;  and  in  the  Azores, 
yellow  lupins  are  very  frequently  sown  among  the  corn 
and  ploughed  in  when  it  is  reaped. 

Lupins  are  plants  which  are  especially  active  in 
dissolving  mineral  matter;  and  the  same  is  true  of 
other  members  of  the  large  family  of  leguminous 
plants  to  which  they  belong — clovers,  vetches,  beans, 
peas.  Moreover,  not  only  these  but  other  plants 
dissolve  more  food  than  they  need  for  their  own 
immediate  use  and  leave  it  in  the  soil,  making  it 
easier  therefore  for  their  successors  to  find  nourish- 
ment. 

This,  then,  is  another  important  service  rendered 
by  the  wild  crops  which  have  grown  for  ages  past  on 
what  are  now  the  best  soils  in  the  world  for  the 
farmer's  purposes.  Whether  these  crops  be  trees,  or 
shrubs,  or  herbage,  they  have  not  only  brought  subsoil 
up  to  the  surface,  but  they  have,  at  least  in  some 
cases,  dissolved  more  than  they  have  used,  and  have 
left  it  all  ready  for  the  crops  which  follow  to  make 
use  of. 

But  even  this  is  far  from  exhausting  their  very 
important  list  of  services.  Indeed,  the  most  impor- 
tant of  all  has  yet  to  be  mentioned. 

Animals  cannot  live  either  upon  mineral  matter  or 
upon  gases,  though  they  need  both,  until  these  have 
been  made  ready  for  them,  which  they  must  be  in  the 
first  instance  by  vegetables. 

Plants  are  more  independent,  for  they  can  make  use 


148  Food  from  the  Soil 

of  mineral  matter,  and  of  gases ;  but  they,  too,  need  a 
little  organic  matter  as  well,  either  animal  or  vegetable. 
Some  plants  need  more  than  others;  but  no  soil  is 
really  fertile  which  does  not  contain  at  least  some 
small  amount.  As  has  been  shown,  however,  no  soil 
is  absolutely  lacking  in  this  important  ingredient,  for 
wherever  plants  have  grown,  or  animals,  however 
lowly,  have  lived,  there  they  have  left  their  remains. 

Why  plants  should  need  organic  matter  is  another 
and  more  difficult  question,  which  seems  to  be  at 
present  unanswerable.  All  organic  remains,  of  course, 
contain  some  mineral  matter ;  but  this  the  plant  can 
get  from  the  soil.  They  all  also  contain  much  carbon ; 
but  this  the  plant  can  get  without  their  help  from  the 
air.  And  finally,  they  all  contain  nitrogen  in  some  one 
or  more  of  its  compounds;  and  it  is  this  nitrogen 
which  the  plant  wants,  and  cannot  apparently  get, 
in  sufficient  quantity,  except  from  organic  matter. 

There  is  an  abundant  supply  of  nitrogen  in  the  air, 
however,  and  why  plants  cannot  help  themselves  to  it 
— when  they  can,  and  do,  take  up  carbon  dioxide  from 
the  same  source — one  cannot  say ;  but  such  is  the  fact. 
Both  are  gases;  and,  as  nearly  four-fifths  of  the  air 
consists  of  nitrogen,  there  is  certainly  no  lack  of  it. 
However,  the  plant  takes  the  one  up  by  its  leaves,  as 
will  be  seen  in  the  following  chapter;  and  does  not 
take  the  other,  much  as  it  wants  it. 

All  animal  and  vegetable  matter,  then,  contains 
nitrogen ;  and  as  all  plants,  whether  lichens  and  mosses, 
or  oaks  and  palms,  must  have  some  amount  of  it,  they 
most  of  them  get  it  from  this  source — the  decayed 
organic  matter  in  the  soil. 

But  there  are  others  which  get  it  equally  well  from 


Food  from  the  Soil  149 

living  matter.  The  mistletoe  and  other  similar  plants 
get  this,  as  well  as  other  food,  from  the  living  trees  or 
plants  upon  which  they  grow.  And  other  plants,  again, 
sometimes  turn  the  tables  on  the  animal  world,  and 
actually  devour  living  insects. 

The  plant  called  Venus'  Fly-trap  is  one  of  these 
insect-eaters,  and  a  very  curious  plant  it  is.  Its  leaves 
end  in  two  lobes,  on  each  of  which  are  three  delicate 
hairs,  so  placed  as  to  form  a  triangle,  and  in  such  a 
position  that  it  is  almost  impossible  for  any  insect 
alighting  upon  the  leaf  to  help  touching  them.  As 
long  as  the  leaf  only  is  touched,  no  harm  is  done,  but 
if  but  the  tip  of  one  of  these  magic  hairs  be  touched, 
the  leaf  closes  instantly  upon  the  victim,  and  does  not 
re-open  until  it  has  sucked  it  dry !  The  trap  will  close 
equally  upon  a  dead,  dry  fly,  or  any  other  substance 
placed  upon  it,  but  it  re-opens  almost  immediately, 
when  the  plant,  by  some  mysterious  instinct,  discovers 
that  the  morsel  is  indigestible. 

A  large  blue -bottle  will  be  seized  at  once,  and 
squeezed  so  tight  that  escape  is  impossible.  But  a 
meal  of  this  sort  seems  to  be  very  satisfying,  for  in  one 
instance  the  leaf  did  not  open  again  for  twenty-four 
days,  and  when  it  did,  though  the  dry  remains  of  the 
fly  were  removed,  no  attempt  to  catch  more  was  made 
until  several  days  later.  There  was  a  similar  result  in 
the  case  of  caterpillars,  raw  meat,  and  spiders.  All 
are  digested  by  means  of  an  acid  which  the  leaf  pours 
out  upon  them. 

It  is  a  curious  fact,  that  the  dropping  of  water  upon 
the  trap  does  not  make  it  close,  unless  the  sun  is 
shining,  or  has  been  shining  immediately  before,  upon 
it  In  this  case,  the  plant,  not  being  prepared  for  rain, 


150  Food  from  the  Soil 

seems  to  be  for  the  moment  deceived.  Rain  usually 
comes  when  the  sky  is  cloudy,  and  then  the  leaf, 
knowing  apparently  what  to  expect,  takes  no  notice. 
If  it  closed  for  rain,  it  would  of  course  often  lose  a 
meal. 

One  of  these  plants,  having  six  leaves,  has  been 
known  to  comfortably  digest  twelve  flies,  or  twelve 
good-sized  spiders,  at  once,  one  for  each  lobe,  after 
which  it  was  satisfied  for  some  time. 

Venus'  Fly-trap  is  found  only  in  Carolina ;  but  we 
have  carnivorous  plants  in  England,  and  it  seems  very 
possible  that  many  plants,  hitherto  unsuspected  of  it, 
feed  upon  insects  when  they  have  the  opportunity. 

The  Sundews,  British  plants  nearly  related  to  the 
Fly-trap,  openly  catch  prey,  and  are  frequently  dis- 
figured by  the  remains  of  insects.  Their  leaves  are 
fringed,  as  well  as  scattered  over,  with  red  hairs.  Each 
hair  has  a  shining  drop  on  its  tip,  which,  lovely  and 
innocent  as  it  looks,  serves  only  to  entrap  the  insect 
touching  it.  Dragon-flies  seem  to  be  attracted  and 
fascinated  by  these  glistening  beads,  for  they  have 
been  observed  to  hover  over  the  leaf,  and  then  to  dart 
down  upon  it  and  be  hopelessly  caught  by  the  folding 
of  the  tentacles.  In  the  small  space  of  one  square 
foot,  six  Sundews  have  been  seen  growing  at  once, 
every  one  of  which  had  secured  a  dragon-fly,  while  one 
had  even  caught  two.  The  plants  were  young,  and 
the  leaves  in  some  cases  were  smaller  than  the  prey, 
whose  wings  were  two  inches  across,  while  their  bodies 
were  an  inch  and  a  half  long;  but  chance  of  escape 
there  seemed  to  be  none  for  them. 

The  Bladderwort  has  been  seen  to  catch  newly- 
hatched  roach  and  also  worms,  by  means  of  its 


Food  from  the  Soil  151 

bladders;  and  the  Butterwort  catches  its  victims  by 
means  of  the  sticky  glands  with  which  its  leaves  are 
thickly  covered,  rolling  up  its  edges  over  them  and 
undoubtedly  eating  them. 

The  various  Pitcher-plants  also  feed  upon  the  large 
number  of  insects  drowned  in  their  receptacles,  which 
are  from  two  or  three  to  as  much  as  eighteen  inches 
deep,  and  always  contain  water. 

But,  whether  or  no  many  plants  are  actual  flesh- 
eaters,  it  is  certain  that  they  all  need  nitrogen;  and 
other  food,  however  abundant,  will  not  be  enough  for 
them,  or  enable  them  to  grow  properly,  if  they  be 
stinted  in  this  respect.  Their  more  usual  way  of 
obtaining  it,  however,  is  from  the  soil,  or  from  the  air ; 
but  in  neither  case  can  they  take  the  pure  gas  itself; 
it  must  be  in  the  form  of  a  compound  before  they  can 
make  any  use  of  it. 

By  way  of  trying  whether  plants  could  do  without 
nitrogen,  other  than  that  by  which  they  are  surrounded 
in  the  air,  three  pots  were  filled  with  a  soil  of  sand  and 
brick-dust,  from  which  all  animal  and  vegetable  matter 
had  been  removed.  A  couple  of  sunflower-seeds  were 
planted  in  each,  and  all  three  were  watered  with  pure, 
distilled  water,  containing  no  food  whatever. 

The  plants  in  the  first  pot  turned  out  mere  dwarfs, 
as  was  to  be  expected ;  those  in  the  second  were  not 
much  better,  though  they  had  had  a  small  quantity  of 
clover-ashes  given  them ;  but  those  in  the  third  were 
almost  as  large  as  the  finest  specimens  grown  in  the 
garden,  for  they  had  been  supplied  with  a  compound 
of  nitrogen,  in  the  form  of  potassium  nitrate;  and 
while  the  two  first  had  managed  to  get  only  about  the 
thirtieth  part  of  a  grain  of  nitrogen  from  the  air,  these 


152  Food  from  the  Soil 

had  taken  sixty-six  times  as  much  from  the  soil.  The 
quantity  is  still  very  small,  of  course,  only  two  grains 
and  a  fifth ;  but  it  strikingly  illustrates  the  immense 
importance  of  small,  and  even  minute  quantities,  since 
it  made  the  whole  difference  in  the  growth  of  the 
plants. 

The  dwarf  sunflowers  obtained  their  small  fraction 
of  nitrogen  from  the  air ;  but  this  is  no  contradiction 
to  what  has  been  previously  said,  for  they  did  not  take 
pure  nitrogen,  but  ammonia,  which  is  a  compound  of 
nitrogen  and  hydrogen. 

There  is  always  some  very  minute  quantity  of 
ammonia  in  the  air — about  one  part  in  a  million — and 
there  seems  to  be  no  doubt  that  plants  can  and  do 
take  this  up  by  their  leaves,  for  they  thrive  all  the  better 
when  the  quantity  is  artificially  increased.  But  they 
take  it  up  also,  and  in  larger  quantities,  by  their  roots, 
when  it  has  been  absorbed  by  the  soil,  or  brought 
down  to  it  by  rain,  snow,  and  dew. 

The  quantity  of  nitrogen  thus  washed  down  in 
combination  with  hydrogen  in  the  course  of  the  year 
seems  to  be  from  about  2  Ib.  to  nearly  21  Ib.  per 
acre;  but  the  average  is  about  4^  Ib.  to  the  acre — 
4!  Ib.  spread  over  an  acre  of  ground !  Considering 
that  there  are  7,000  grains  in  a  pound,  and  that  the 
sunflowers,  even  when  they  had  more  within  reach, 
took  up  little  more  than  a  grain  of  nitrogen  apiece, 
perhaps  the  quantity  may  not  sound  so  very  small. 

But  an  acre  of  wheat,  yielding  twenty-eight  bushels, 
takes  up  about  45 J  Ib.  of  nitrogen;  while  an  acre  of 
clover  uses  108  Ib. ! 

And  even  this  does  not  at  all  represent  the  whole  of 
what  is  required ;  for  the  roots,  however  many,  cannot 


Food  from  the  Soil  153 

possibly  be  in  close  contact  with  all  parts  of  the  soil 
at  once,  and  they  can  no  more  make  use  of  all  the 
nitrogen  than  they  can  of  all  the  mineral  matter,  or 
all  the  moisture ;  so  that  of  this,  as  well  as  of  the  rest, 
they  need  much  more  than  they  can  actually  use. 

An  acre  of  soil,  one  foot  deep,  weighs  some 
4,000,000  Ib. ;  and  just  a  few  pounds  of  nitrogen 
equally  mixed  in  this  would  be  almost  as  difficult  to 
find  as  a  needle  in  a  haystack ;  and  even  if  there  were 
actually  as  much  as  the  crop  required,  the  roots  could 
not  reach  it. 

A  heavy  wheat-crop  needs,  therefore,  nearly  300  Ibs. 
of  nitrogen  to  the  acre,  or  about  six  times  as  much  as  it 
actually  takes  up.  And  this  it  certainly  cannot  get  from 
the  ammonia  in  the  air,  or  from  that  which  is  washed 
from  it  into  the  soil. 

But  when  organic  matter  decays,  whether  it  be 
animal  or  vegetable,  the  nitrogen  contained  in  it 
combines  with  other  gases  to  form  not  only  ammonia, 
but  also  nitric  acid. 

Much  of  the  ammonia  streams  off  into  the  air,  but 
the  nitric  acid  remains  and  combines  with  potash, 
soda,  lime,  magnesia,  or  iron,  with  which  it  forms 
nitrates.  These  nitrates  are  easily  dissolved,  and  it  is 
from  them  that  the  plants  obtain  their  nitric  acid — 
very  much  diluted,  of  course,  as  is  all  the  food  which 
they  take  from  the  soil. 

As  already  remarked,  plants  have  the  power  of  de- 
composing such  salts,  taking  one  ingredient  and  leaving 
the  other.  The  sunflowers  which  throve  so  well  in  the 
experiment  described,  were  supplied  with  potassium 
nitrate,  and  from  this  they  were  able  to  extract  the 
nitric  acid  which  they  needed. 


154  Food  from  the  Soil 

Nitrates  are  very  soluble,  and  in  damp  soil  they 
are  formed  and  dissolved  so  quickly  as  seldom  to  be 
visible.  But  it  is  not  so  in  regions  where  rain  falls 
either  at  certain  seasons  only,  or  very  rarely.  The 
most  fertile  soils  of  Bengal,  for  instance,  are  often 
covered  during  the  dry  season  with  a  white  crust  of 
some  of  these  salts,  chiefly  potassium  nitrate,  other- 
wise called  nitre  and  saltpetre.  The  crust  vanishes  as 
soon  as  the  rain  comes,  being  dissolved  and  washed 
into  the  soil,  which  is  so  rich  as  to  bear  two  or  three 
crops  a  year. 

Wherever  these  nitrates  are  formed,  whether,  as  in 
England,  they  are  dissolved  almost  at  once,  or  whether, 
as  in  dry  lands,  they  accumulate  and  encrust  the  soil, 
they  are  formed  by  the  decay  of  animal  and  vegetable 
matter.  And  what,  it  may  be  asked,  causes  this 
decay  ?  Not  the  action  of  the  air  ;  for  in  perfectly  pure 
air  organic  substances  do  not  decay.  The  change  is 
brought  about  by  the  action  of  living  organisms, 
invisible,  but  very  potent  in  their  effects. 

We  have  all  heard  enough  about  '  germs '  of  late  to 
know  that  they  swarm  in  the  air ;  but  they  also  swarm 
in  all  the  moist  places  of  the  earth.  Some  few  classes 
of  them  are  dangerous  to  man,  and  produce  diseases 
of  various  kinds;  others  are  not  only  harmless,  but 
productive  of  the  greatest  good. 

All  decay,  fermentation,  or  putrefaction,  whichever 
we  call  it,  is  their  work ;  and  when  we  say  '  work,'  all 
that  is  meant  is  their  living,  growing,  multiplying, 
which  they  cannot  do  without  feeding.  There  is  an 
immense  variety  of  them,  and  they  produce  different 
results  according  to  their  different  modes  of  feeding. 
The  yeast  which  is  put  into  dough,  the  '  mould '  which 


Food  from  the  Soil  155 

grows  upon  paste,  or  jam,  are  all  of  similar  nature, 
and  all  produce  alterations  in  the  substance  which 
they  attack.  When  we  like  the  result  of  these 
alterations,  we  call  the  process  'fermentation';  and 
when  we  do  not  like  it,  we  call  it  '  putrefaction ' ;  but 
both  are  substantially  the  same,  for  both  are  the  result 
of  decomposition.  Grape- juice,  apple-juice,  and  wort, 
are  converted  by  these  'ferments'  into  wine,  cider, 
and  beer  respectively;  and  another  ferment  again 
alters  wine  yet  further,  and  turns  it  into  vinegar. 

It  is  these  living  organisms  which  bring  about  all 
decay  of  animal  or  vegetable  matter,  whether  in  the 
soil  or  elsewhere. 

Their  work  in  the  soil  seems  to  go  on  chiefly  in  the 
upper  nine  inches,  and  most  rapidly  when  the  weather 
is  warm  and  damp. 

The  multitudes  of  leaves  drawn  in  by  worms,  the 
old  roots  of  former  crops,  or  green  crops  which  have 
been  grown  only  that  they  may  be  ploughed  in — all 
are  decayed,  and  so  converted  into  food,  of  which  the 
next  crop  can  avail  itself. 

As  has  been  more  than  once  remarked,  all  soils 
contain  more  or  less  organic  matter ;  but  unless  the 
amount  is  very  large,  as  it  is  in  the  Russian  Black 
earth  region,  Manitoba,  and  elsewhere,  not  much  of 
the  nitrates  formed  by  its  decay  will  be  left  in  the 
upper  twenty-seven  inches  of  the  soil  after  a  crop  of 
corn  has  been  grown  in  it.  Organic  matter  there  will 
still  be,  but  decay  is  gradual,  and  nitrates  take  time  to 
form  ;  so  the  farmer  must  supply  the  want  in  one  way 
or  other. 

In  former  days,  till  within  the  last  century  in  fact, 
his  way  of  doing  so  was  simpje.  He  merely  ploughed 


156  Food  from  the  Soil 

up  the  field,  and  let  it  alone  to  recover  itself;  in  other 
words,  he  allowed  it  to  lie  fallow. 

And  what  goes  on  in  a  fallow  field  ?  Generally 
speaking  it  is,  or  was,  both  ploughed  and  harrowed 
repeatedly,  so  that  the  soil  might  be  exposed  as  much 
as  possible  to  the  action  of  the  air  and  rain,  by  which 
the  mineral  matter  would  be  dissolved  ready  for  the 
next  crop.  Then  in  the  winter  the  soil  would  be  yet 
further  broken  up  by  the  freezing  of  the  moisture  in 
its  pores,  which  would  separate  grain  from  grain, 
reducing  it  to  powder  in  a  way  that  no  plough  or 
harrow  yet  invented  can  do.  The  crumbling  of  the 
soil  would  make  it  yet  more  easily  dissolved  by  water, 
as  well  as  more  easy  for  roots  to  penetrate ;  nor  must 
it  by  any  means  be  forgotten  that  while  the  land  lay 
idle  the  worms  were  busy,  turning  it  over,  also,  grain 
by  grain,  and  enriching  it  as  already  described.  And 
though  the  farmer  did  not  sow  it,  seeds  were  sown  by 
the  wind,  and  a  crop  of  weeds  was  certain  to  spring 
up,  whose  half-decayed  leaves  the  worms  would  drag 
into  their  burrows.  The  whole  wild  crop,  too,  would 
be  ploughed  in,  and,  with  the  roots  of  the  farmer's  last 
crop,  would  be  gradually  decayed.  The  soil  when 
damp  would  absorb  ammonia  from  the  air,  and 
ammonia  would  also  be  brought  down  by  rain  and 
snow,  and  converted  into  nitric  acid,  which  would 
combine  with  some  of  the  minerals  already  mentioned; 
and  in  this  way,  as  well  as  by  the  decay  of  the  organic 
matter  left  in,  or  added  to,  the  soil,  a  fresh  supply  of 
nitrates  would  be  prepared. 


XII. 

LEAVES  AND   THEIR  WORK 

ALL  the  plant-food  which  we  have  yet  considered  is 
drawn  from  the  soil,  with  the  exception  of  the  minute 
quantity  of  ammonia  taken  in  by  the  leaves  from  the 
air.  But  this  latter  is  far  from  being  all  that  the 
leaves  contribute  to  the  food-supply. 

The  roots  furnish  food  from  the  soil — mineral  and 
organic  matter ;  and  the  leaves  furnish  food  from  the 
air — the  carbon,  which  makes  up  about  half  the  dry 
weight  of  a  plant — half  its  weight,  that  is,  when  all  the 
water  has  been  removed  from  it.  Roots  and  leaves, 
therefore,  supply  about  an  equal  amount  of  food. 

But  the  leaves  do  more  than  merely  supply  food ; 
they  prepare  it  for  the  whole  plant,  both  that  which 
they  themselves  take  up,  and  that  which  is  procured 
by  the  roots.  Leaves  are  the  food-manufacturers; 
and  it  is  they  which  combine  the  various  materials, 
and  distribute  food  to  the  several  parts. 

Nitrogen,  the  food  derived  from  organic  matter, 
which  we  have  last  considered,  is  needed  in  some 
combination  or  other  by  all  parts  of  a  plant,  but 
especially  by  the  seed.  No  one  needs  to  be  told 
that  grain  is  more  nourishing  than  straw;  but  the 


158  Leaves  and  their  Work 

reason  why  it  is  more  nourishing  is  that  it  contains 
more  nitrogen,  in  the  form  of  nitrogenous  or  albu- 
minous compounds,  commonly  called  albuminoids, 
because  they  resemble  the  albumin,  or  white,  of  an 
egg.  There  is  albumin  in  the  liquid  part  of  blood,  and 
there  is  albumin  in  the  seeds  and  juices  of  plants. 
There  is  fibrin  in  flesh  and  in  the  thick  red  part 
of  blood ;  and  there  is  vegetable  fibrin,  a  sticky 
substance  usually  called  gluten,  in  flour.  There  is 
casein  in  milk  and  cheese,  and  there  is  casein  in  beans. 

These  various  substances  are  all  jelly-like,  and  are 
very  similar  in  composition,  whether  they  are  obtained 
from  animal  or  from  vegetable  matter.  They  are 
called  nitrogenous  because  it  is  the  nitrogen  they  con- 
tain which  gives  them  their  especial  characteristics 
and  value  as  food ;  but  the  nitrogen  in  them  forms 
less  than  a  seventh  part  of  their  substance,  more  than 
half  of  which  consists  of  carbon.  In  addition  to  this 
large  amount  of  carbon,  most  of  the  nitrogenous  com- 
pounds contain  sulphur,  besides  hydrogen  and  oxygen, 
and  most  of  them  phosphorus  as  well.  They  could 
not  therefore  be  formed  without  the  help  of  mineral 
matter  from  the  soil,  and  of  carbon  from  the  air ;  the 
nitrogen  being  obtained  both  from  the  nitrates  in  the 
soil  and  from  the  ammonia  in  the  air. 

All  the  corn  crops,  as  well  as  the  clovers,  beans, 
peas,  and  other  leguminous  plants,  require  much 
nitrogen,  especially  when  their  seeds  are  forming  and 
ripening ;  but  by  the  time  they  have  done  blossoming, 
they  have  taken  up  all  they  want,  and  it  is  being  pre- 
pared and  compounded  by  the  leaves,  to  be  gradually 
passed  on  by  them  to  the  growing  seeds  as  they  need 
It.  Grass,  therefore,  is  not  cut  for  hay  until  after  it 


Leaves  and  their  Work  159 

has  blossomed,  because  it  then  contains  most  nitrogen 
and  is  most  nutritious.  For  the  nitrogenous  com- 
pounds are  the  flesh-forming  part  of  all  food,  animal 
or  vegetable. 

They  are  very  much  alike  in  composition,  as  has 
been  said,  and  substances  which  are  closely  similar 
may  be  obtained  both  from  a  beef-steak  and  a  cauli- 
flower ;  from  the  white  of  an  egg  and  from  a  cabbage  ; 
from  milk  curd,  and  from  peas  and  beans,  of  which  the 
Chinese  do  actually  make  a  vegetable  cheese. 

Quantity  for  quantity,  a  cabbage  is,  indeed,  less 
nutritious  than  the  white  of  an  egg  ;  but  the 
cabbage  contains  a  similar  substance.  It  would,  how- 
ever, be  necessary  to  eat  a  much  larger  weight  of 
cabbage  to  obtain  as  much  flesh-forming  food  as  is 
contained  in  an  egg. 

And  then,  again,  though  the  nitrogenous  compounds 
obtained  from  flesh  and  vegetables  are  similar — so 
closely  similar  even  as  to  appear  almost  identical— they 
are  not  absolutely  identical,  and  it  would  be  rash, 
therefore,  to  conclude  that  they  are  equally  nutritious. 
For,  if  one  thing  be  more  plain  than  another,  from 
what  has  been  said  in  the  previous  pages,  it  is  the 
immense  importance  belonging  to  little  things — to 
trifles  so  minute  as  almost,  or  quite,  to  escape  detec- 
tion. 

Let  us  remember  the  vineyards  growing  side  by  side 
— the  treatment  the  same,  the  soil  so  apparently  the 
same,  that  the  difference  cannot  be  detected — and  yet 
the  wine  from  the  one  is  worth,  and  fetches  in  the 
market,  twenty  times  as  much  as  the  other !  The  vines 
being  of  the  same  species,  and  all  other  things  being 
equally  enjoyed  by  both,  it  follows  that  the  difference 


160  Leaves  and  their   Work 

in  quality  must  be  caused  by  some  slight  difference  in 
the  soil,  which  is  so  slight  as  to  be  undiscoverable. 

If,  therefore,  so  slight  a  difference  in  the  vine's  food 
can  make  so  large  a  difference  in  its  produce,  it  seems 
altogether  rash  to  conclude  that  the  cheese  of  beans  is  as 
nutritious  as  the  cheese  of  milk ;  or  that  it  makes  no 
difference  whether  one  dines  on  cauliflower  or  beef. 

All  plants  do  not  contain  an  equal  amount  of  the  nitro- 
genous compounds ;  and  even  the  same  plant  contains 
very  different  quantities  in  different  parts,  and  also  at 
different  stages  in  its  life. 

Leaves  and  stalks  are  less  nutritious  than  seed,  and 
the  seed  itself  is  most  nutritious"  when  it  is  ripe,  as  it 
is  then  that  it  contains  the  largest  amount  of  nitrogen. 
Ripe  ears  of  maize,  for  instance,  contain  ten  times  as 
much  nitrogen  as  green  ears  ;  but  even  then  they  con- 
tain less  than  either  rye,  oats  or  wheat,  and  less  than 
half  the  amount  contained  in  peas,  beans,  or  lentils. 
Lentils,  indeed,  are  among  the  most  valuable  of  the 
seeds  used  as  food,  for  nearly  a  fourth  part  of  their 
substance  consists  of  albuminous,  or  nitrogenous,  com- 
pounds. As  for  potatoes,  they  are  very  low  down  in 
the  scale  of  food,  for  they  are  chiefly  water,  and  the 
amount  of  flesh-forming  food  which  they  yield  is  only 
two  parts  in  a  hundred,  less,  that  is,  than  meadow-grass 
before  it  has  blossomed. 

We  must  now  look  a  little  more  closely  at  the  work 
done  by  the  leaves,  for  it  is  they,  as  has  been  said, 
which  supply  the  plant  with  carbon.  Carbon  is 
wanted  for  the  nitrogenous  compounds ;  carbon  is 
wanted  for  the  plant's  skeleton,  and  for  its  wood ; 
carbon  is  wanted  for  the  manufacture  also  of  starch, 
gum,  sugar,  oils,  acids,  and  the  various  aromatic 


Leaves  and  their  Work  161 

compounds  to  which  plants  and  flowers  owe  their 
fragrance. 

And  this  carbon  the  leaves  have  no  difficulty  in  pro- 
viding, so  long  as  the  roots  do  their  part ;  but  if  they 
fail,  the  leaves  must  fail  too.  For  the  plant  is  a  whole, 
a  body,  of  which  every  part  is  dependent  upon  the 
rest.  But  while  the  roots  can  do  their  work  in  the 
dark,  the  leaves  are  perfectly  helpless  without  light. 

Cfive  the  plant  light,  however,  together  with  the 
proper  food  which  the  roots  collect  from  the  soil,  and 
then  the  leaves  have  no  difficulty  in  adding  the  carbon 
which  is  their  share. 

And  why,  it  may  be  asked,  should  they  have  any 
difficulty  ?  Since  the  whole  plant  wants  it,  and  has  to 
get  it  through  the  leaves,  surely  it  would  be  more 
strange  if  the  leaves  could  not  find  it,  since  they  live  in 
the  air,  where  it  is. 

Perhaps ;  but  the  proportion  in  the  air  is  extremely 
small,  though  the  amount  sounds  large  ;  and  leaves 
cannot  wander  in  search  of  food,  as  roots  do.  The 
food  must  come  to  them,  as  they  cannot  go  to  the 
food.  Carbon  exists  in  the  air,  combined  with  oxygen, 
as  the  gas  carbon-dioxide,  or  carbonic  acid ;  and  there 
are  about  three  billion  four  hundred  million  tons  of 
the  gas  in  the  atmosphere  of  the  whole  globe.  The 
figures  convey  little  to  one's  mind,  but,  at  all  events, 
the  amount  sounds  comfortably  large — sufficient,  at 
least,  to  preserve  the  vegetable  world  from  all  risk  of 
a  dearth  of  this  species  of  food. 

And  yet  it  has  been  calculated  that,  if  used  at  the 
present  rate,  the  whole  of  this  enormous  supply  would 
be  exhausted  in  about  a  hundred  years,  after  which 

II 


1 62  Leaves  and  their  Work 

not  so  much  as  a  blade  of  grass  could  exist  until  the 
supply  were  renewed. 

Let  us  put  it  in  another  way.  The  amount  is  large 
in  itself,  but  it  is  enormously  diluted— so  much  diluted, 
indeed,  as  to  be  hardly  reckoned  at  all !  That  is,  in 
speaking  of  the  air,  we  commonly  say  that  it  consists 
of  about  four-fifths  nitrogen  and  gne-fifth  oxygen, 
leaving  the  carbon  -  dioxide  out  of  the  account 
altogether.  For,  except  in  confined  spaces,  and  under 
special  circumstances,  one  part  in  twenty-five  thou- 
sand is  all  the  carbon-dioxide  that  the  air  contains, 
so  vast  is  the  space  through  which  the  gas  is  dis- 
tributed. There  is  just  enough  carbon-dioxide  in  the 
air  to  furnish  twenty-eight  tons  to  every  acre  all  over 
the  globe — twenty-eight  tons  of  gas,  or  eight  tons  of 
carbon  ! 

But  an  acre  of  beech-forest  would  use  up  the  whole 
of  this  allowance  in  about  eight  years ;  and  it  would 
not  last  an  acre  of  bananas  much  more  than  one  year. 

All  plants  do  not,  it  is  true,  use  up  carbon  at  these 
rates;  but  it  is  evident  that  the  supply  needs  pretty 
constant  renewing.  And  it  is  renewed  day  by  day, 
hour  by  hour ;  nor,  so  long  as  animals  breathe,  and  fires 
burn,  and  vegetable  matter  decays,  is  there  any  danger 
that  the  supply  will  run  short. 

Whenever  carbon  unites  with  oxygen  it  is  what  we 
call  burnt,  and  carbon- dioxide  is  produced.  The 
carbon  disappears,  but  it  is  not  .destroyed — it  has  only 
been  made  invisible  by  combining  with  oxygen.  When- 
ever, therefore,  animal  or  vegetable  matter  decays,  the 
carbon  which  it  contains  is  slowly  burnt,  and  the  gas 
passes  off  into  the  air  as  it  forms,  unless  prevented, 
as  it  is,  in  a  great  measure,  when  produced  underground 


Leaves  and  their  Work  163 

Again,  when  animals  or  plants  breathe,  the  oxygen 
which  they  inhale  unites  with,  and  burns,  part  of  the 
carbon  of  their  food,  and  the  gas  is  breathed  back  into 
the  air.  The  air  we  inhale  contains  but  one  part  in 
twenty-five  thousand  of  carbon-dioxide  ;  but  the  air 
we  exhale  contains  much  more — from  three  to  six  per 
cent.  Plants,  however,  breathe  very  much  more 
slowly  than  any  warm-blooded  animals,  and  give  off 
less  carbon-dioxide  in  proportion. 

Whenever  carbon  is  burnt  by  combining  with  oxygen, 
whether  in  food,  coal,  wood,  gas,  oil,  candle,  or  in 
decaying  vegetable-matter,  there  carbon-dioxide  is 
formed.  It  is  being  constantly  poured  into  the  air, 
therefore,  by  men  and  animals,  by  the  chimneys  of 
factories  and  houses,  by  volcanoes,  and  by  the  soil. 

But  it  is  not  produced  in  anything  like  equal  quan- 
tities in  all  parts  of  the  world.  Very  little  is  returned 
to  the  air  above  the  ocean,  and  that  little  chiefly  by 
passing  vessels  ;  and  as  there  is  more  ocean  than  land 
in  the  southern  hemisphere,  much  less  is  produced 
there  than  in  the  northern  hemisphere,  which  is  chiefly 
land. 

Then,  again,  the  eastern  hemisphere  is  much  more 
densely  populated  than  the  western,  besides  having, 
of  course,  many  more  factories,  furnaces,  and  engines 
of  all  sorts,  which  are  constantly  burning  carbon.  It 
might  seem  not  improbable,  therefore,  that  some  parts 
of  the  world,  such  as  the  islands  of  the  Pacific,  should 
be  at  times  in  danger  of  not  having  carbon-dioxide 
enough  to  supply  the  wants  of  their  vegetation, 
especially  when  we  consider  that  bananas,  which  need 
such  large  quantities,  form  an  important  item  in  their 
crops. 


164  Leaves  and  their  Work 

But  the  fact  is  not  so;  for  the  supply  is  equally 
distributed.  More  fires  are  kept  burning,  and  more 
carbon-dioxide  is  produced  in  winter,  when  the  trees 
are  leafless  and  do  not  want  it,  than  in  the  summer, 
when  they  do.  And  yet  we  are  not  choked  by  it,  or 
even  inconvenienced  by  it,  in  the  winter  months,  so  it 
must  be  got  rid  of  somehow.  For,  if  there  were  two 
per  cent,  in  the  air,  we  should  have  severe  headache, 
and  ten  per  cent,  would  suffocate  us.  What,  then, 
becomes  of  it  ?  Roughly  speaking,  we  may  say  that 
the  carbon-dioxide  produced  during  the  winter  of  the 
north  goes  to  feed  the  vegetation  of  the  south — the 
thistles,  clover  and  grass,  for  instance,  of  the  Pampas, 
which  are  flourishing  in  all  their  luxuriance  while 
winter  prevails  with  us.  And  it  goes,  to  some  extent, 
at  least,  because  the  leaves  of  the  southern  hemisphere 
draw  it  thither. 

The  ocean  of  air  which  surrounds  the  world  is  not, 
it  must  be  remembered,  a  compound,  but  a  mixture. 
If  we  could  see  it  we  should  find  oxygen,  nitrogen, 
carbon-dioxide,  ammonia,  all  perfectly  mixed,  but 
perfectly  distinct.  The  combination  of  two  gases, 
oxygen  and  hydrogen,  makes  water — a  liquid  entirely 
different  from  both ;  but  there  is  no  such  combination 
and  alteration  in  the  gases  of  the  air.  Each  keeps  its 
own  character  ;  but,  though  all  are  of  different  weights, 
they  are  so  thoroughly  and  perfectly  mixed  that,  except 
under  special  circumstances,  there  is  but  little  appreci- 
able difference  in  the  air  of  different  parts  of  the  world. 

Carbon-dioxide  is  the  heaviest  of  these  gases,  and  it 
is  more  than  twice  the  weight  of  the  mixture  of  these 
gases  which  we  call  the  air.  Where  it  is  poured  out  from 
cracks  in  the  earth,  as  it  is  largely  in  some  volcanic 


Leaves  and  their  Work  165 

districts,  its  weight  keeps  it  down  for  a  time  near  the 
ground,  but  gradually,  in  obedience  to  a  mysterious  law, 
it  rises  and  spreads  through  the  air.  Its  weight  draws 
it  down  to  the  earth,  or,  more  correctly  speaking,  the 
earth  attracts  it  to  itself  more  than  it  attracts  either 
oxygen  or  nitrogen.  It  is  heavy,  because  the  earth 
attracts  it,  just  as  a  stone  is  heavier  than  a  feather. 
But  it  rises. 

We  should  be  surprised  to  see  a  stone  thrown  from 
our  hand  continue  to  mount  upwards  instead  of  falling 
to  the  ground,  but  this  is  precisely  what  carbon-dioxide 
does,  and  we  can  but  state  the  fact  without  explaining 
it.  Gases,  no  matter  what  their  weight,  are  obliged  to 
mix  one  with  the  other. 

Put  into  a  bottle  first  some  heavy  carbon-dioxide, 
then  some  oxygen,  which  is  lighter,  nitrogen,  which  is 
lighter  still,  and,  lastly,  hydrogen,  the  lightest  of  all^ 
which  is  so  light  that  it  has  to  be  poured  upwards,  and, 
though  at  first  the  heaviest  gas  will  be  at  the  bottom, 
before  long  all  will  be  perfectly  mixed,  and  there  will 
be  as  much  hydrogen  at  the  bottom  as  at  the  top. 
Carbon-dioxide  moves  more  slowly  than  hydrogen, 
owing  to  its  weight,  but  move  upwards  it  will,  and  that 
without  any  shaking. 

All,  or  part,  of  the  carbon-dioxide  might,  however, 
be  removed  from  this  mixture  without  affecting  the 
other  gases,  if  a  piece  of  caustic  potash  were  intro- 
duced ;  for  this  substance  has  the  power  of  attracting 
and  absorbing  this  particular  gas.  Each  of  the  other 
gases  might  also  be  removed  by  similar  means,  one  by 
one  substance,  and  another  by  another. 

Leaves,  then,  act  upon  carbon-dioxide  in  some  such 
way  as  caustic  potash  does.  They  attract  it  to  them- 


1 66  Leaves  and  their   Work 

selves  and  absorb  it ;  but,  by  so  doing,  they  are  con- 
stantly diminishing  the  amount  of  the  gas  in  the  air 
immediately  surrounding  them  ;  and  as,  according  to 
the  law  of  their  being,  gases  must  mix  equally  one  with 
the  other,  more  carbon-dioxide  flows  in  to  supply  the 
place  of  that  which  is  absorbed.  Streams  of  the  gas 
are  therefore  constantly  flowing  towards  each  leaf, 
even  when  the  air  is  still ;  when  there  is  wind  the 
whole  air  is,  of  course,  in  motion. 

We  have  now  to  see  what  becomes  of  the  carbon- 
dioxide  when  the  leaves  have  taken  it  up.  As  has 
been  said,  in  most  plants  nearly  one-half  the  dry  sub- 
stance left  when  the  water  is  removed  consists  of 
carbon,  of  which  charcoal  is  an  impure  form.  Carbon 
enters  into  the  composition  of  every  animal  and  vege- 
table substance,  no  matter  how  minute.  It  is  to  be 
found  in  every  part  of  a  plant  from  the  root  upwards, 
but  especially  in  the  seed.  In  the  grains  which  we  use 
as  food  the  quantity  of  carbon  amounts  to  some  forty 
or  fifty  per  cent,  of  the  whole ;  and,  though  the  car- 
bon compounds  are  not,  like  the  nitrogenous  com- 
pounds, flesh-formers,  they  are  equally  important  as 
fat-formers,  and  as  supplying  fuel  to  maintain  the  heat 
of  our  bodies.  The  carbon  of  our  food  is  oxidized, 
burnt,  by  the  oxygen  of  the  air  we  breathe ;  heat  is 
thus  produced,  and  the  greater  part  of  the  carbon  is 
given  back  to  the  air  as  carbon-dioxide. 

One  pound  of  wheat-flour  contains  about  nine  and 
a  half  ounces  of  starch,  and  starch  is  a  compound  of 
carbon,  oxygen  and  hydrogen  ;  but  it  also  contains  two 
ounces  of  gluten — one  of  the  nitrogenous  compounds — 
and  half  of  this  is  carbon ;  and  besides  these  it  con- 
tains smaller  quantities  of  sugar,  gum  and  fat,  and 


Leaves  and  their   Work  i6/ 

these  are  all  carbon  compounds ;  so  that  altogether 
the  pound  of  flour  contains  some  seven  ounces  of 
carbon. 

Some  of  the  palms,  as  the  sago  palm,  use  very  large 
quantities  of  carbon  in  forming  the  starch  of  their 
pith  :  one  tree,  for  instance,  often  yielding  the  extra- 
ordinary amount  of  800  Ibs.  of  starch.  All  the  sugars, 
oils,  gums,  caoutchoucs,  of  the  vegetable  world,  contain 
large  quantities  of  carbon,  and  so  also  do  the  fibres 
of  cotton,  flax,  hemp  and  others. 

But,  as  already   said,   carbon   forms    part  of   the 


Surface  leaf-cells,  with  pores,  magnified. 

structure  of  every  portion  of  a  plant  from  root  to  seed, 
and  it  enters  largely  into  the  composition  of  the 
skeleton,  or  frame-work,  both  of  stems  and  leaves  ;  for 
a  plant's  skeleton  consists  of  fibre,  identical  in  com- 
position with  the  fibres  of  the  cotton  and  other  plants 
used  for  weaving  purposes. 

Now,  both  the  skeleton  and  the  flesh  of  a  plant, 
every  part  of  it,  indeed — roots,  stems,  leaves,  flowers, 
fruit,  seed — consists  either  of  a  single  cell,  or  of  an 
assemblage  of  cells,  which  may  be  compared  with  the 


1 68 


Leaves  and  their  Work 


i  ells  of  a  honeycomb,  except  that  they  vary  extremely 
in  size  and  shape. 

Some  cells  are  so  minute  as  to  be  altogether  invisible 
to  the  naked  eye;  as,  for  instance,  the  spores  of 
lichens  and  fungi,  the  '  germs  '  already  mentioned,  and 
certain  minute  water  plants,  each  and  all  of  which 
consist  of  a  single  cell,  filled,  like  the  honey-cells,  with 
more  or  less  fluid  contents. 

But  the  cells  in  the  flesh  of  a  lemon  are  gigantic  by 
comparison,  being  half  an  inch  long;  the  cells  of 


Transverse  section  of  a  leaf,  magnified. 

fibres  are  often  much  longer  than  this,  and  there  are 
cells  of  all  sizes  between  these,  the  most  usual  size 
being  from  TTTRT  to  -%%-$  of  an  inch  across.  Cells  are  of 
almost  every  possible  shape,  too — globular,  square, 
six-sided,  twelve-sided,  or  quite  irregular,  with  their 
outlines  beautifully  zigzagged  or  waved.  But,  whatever 
their  shape  and  size,  their  walls,  thick  or  thin,  are 
composed  of  the  skeleton  material  mentioned  above, 
which  is  called  after  them  '  cellulose/ 

This  material,  like  cotton  and  other  fibres,  is  com- 
posed in  great  measure  of  carbon,  and,  as  all  plants  in- 


Leaves  and  their  Work  169 

crease  in  size  by  the  multiplication  of  cells,  it  is  evident 
that  they  could  not  grow  at  all  in  air  containing  no 
carbon-dioxide.  Neither  can  they  grow  if  deprived  of 
their  leaves,  for  these  are  the  chief  manufacturers  of 
cellulose  and  other  food.  A  tree  stripped  of  even  half 
its  leaves  will  be  unable  to  make  much  wood,  though  it 
may  manage  to  live. 

The  skin  of  a  leaf  usually  consists  of  a  single  layer  of 
cells,  not  green,  but  colourless  and  transparent,  and 
beneath  these  are  other  cells  containing,  besides  other 
things,  *  leaf-green,'  or  colouring  matter.  It  is  in  these 
lower  cells  that  the  manufacture  of  the  plant's  food  is 
carried  on ;  and,  though  the  process  cannot  be  ex- 
plained, one  or  two  facts  are  certain — it  cannot,  in 
most  plants,  go  on  without  light,  or  in  any  without  the 
leaf-green. 

The  gases  of  the  air  are  able  to  pass  through  the 
cell-walls,  both  in  and  out.  It  must  not  be  forgotten 
that  plants  need  air  for  breathing,  as  well  as  carbon- 
dioxide  for  food  ;  and  though  they  breathe  as  well  as 
feed  by  means  of  their  leaves,  the  two  processes  are 
quite  distinct. 

What  the  plant  does  with  the  carbon-dioxide  is  to 
separate  the  carbon  and  keep  it,  and  to  let  go  most  of 
the  oxygen.  The  two  have  to  be  torn  asunder,  and 
this  is  done  in  the  cells  containing  leaf-green.  But  the 
leaf-green  itself  cannot  be  developed  either  without 
light,  or  without  iron  ;  and  when  developed  it  cannot 
act  in  darkness. 

For  the  supply  of  iron  the  leaves  are,  of  course, 
dependent  upon  the  plant's  roots,  and  if  the  roots  can- 
not find  it,  the  leaves  and  young  stems  remain  yellow 
or  colourless.  Compounds  of  iron  are,  however,  so 


tjo  Leaves  and  tJieir  Work 

very  general  in  all  the  rocks  composing  the  earth's 
crust,  that  it  is  almost  impossible  to  find  any  soil  quite 
without  them. 

But  the  iron  may  be  taken  away  by  artificial  means, 
and  when  this  is  done  the  leaf-green  turns  yellow,  as 
human  beings  do  when  their  blood  contains  too  few 
red  particles,  and  for  precisely  the  same  reason.  Both 
stand  in  need  of  iron.  Iron  oxide  is  reddish  when 
it  contains  the  full  amount  of  oxygen  possible,  and 
green  when  it  contains  less.  Give  the  plant  iron 
and  keep  it  in  the  light,  and  the  grains  of  leaf- 
green  at  once  begin  to  turn  their  proper  colour,  and 
tiny  grains  of  starch  form  within  them. 
.  A  very  little  light,  barely  enough  to  read  by,  will  be 
sufficient  to  make  a  plant  begin  to  turn  green,  but  not 
sufficiently  green  to  enable  it  to  separate  the  carbon ; 
and  therefore  in  dim  light  no  starch  grains  can  be 
formed.  In  ordinary  daylight,  however,  whether  the 
sun  be  shining  directly  upon  the  plant  or  no,  these 
starch-grains  are  being  continually  produced ;  but  the 
brighter  the  light  the  more  briskly  the  manufacture 
goes  on,  up  to  a  certain  point — provided,  that  is,  that 
the  air  contains  carbon-dioxide  wherewith  to  furnish 
the  necessary  supply  of  carbon.  If  it  does  not,  no 
starch,  of  course,  can  be  formed,  no  matter  how  bright 
the  light,  or  how  green  the  leaf-green. 

But  all  air,  unless  artificially  deprived  of  it,  contains 
enough  to  furnish  what  the  plant  requires  in  this 
respect,  thanks  to  the  supplies  which  are  being  con- 
stantly furnished  to  it.  If  the  supply  of  carbon-dioxide 
were  not  renewed,  however,  it  would  be  exhausted,  as 
already  mentioned,  in  about  a  hundred  years  by  the 
present  vegetation  of  the  globe.  But  if  the  world  were 


Leaves  and  their   Work  171 

covered  with  beech-forest,  all  this  gas,  even  though  it 
amounts  to  billions  of  tons,  would  be  gone  in  eight 
years  !  For  one  acre  of  beechwood  takes  about  a  ton 
of  carbon  every  year  ;  and  to  supply  one  ton  of  carbon, 
three  and  a  half  tons  of  carbon-dioxide  gas  are  neces- 
sary. This  is  taken  up  not  only  by  the  leaves,  but 
by  all  the  green  parts  of  a  plant,  leaves,  buds,  stems, 
and  fruit,  so  long  as  these  remain  green  ;  for  it  is  only 
in  the  cells  which  contain  leaf-green  that  starch  is 
manufactured  from  the  gas.  These  green  cells  lie  im- 
mediately underneath  the  thicker-walled  but  transparent 


Surface  leaf-cells,  with  pores,  magnified. 

cells  of  the  surface  which  compose  the  skin;  and  through 
the  skin  the  gas  finds  its  way  into  them. 

The  leaf-pores,  by  which  water  escapes,  are  openings 
in  the  skin  formed  by  two  curved,  lip-like  cells,  which 
gape  open  in  hot,  bright  weather,  and  close  more  or 
less  in  rain,  damp,  and  darkness ;  and  it  is  when  they 
open  most  widely  that  the  manufacture  of  food  goes 
on  most  briskly.  For  it  is  then  that  most  carbon 
is  separated,  and  most  food  is  pumped  up  from  the 
roots,  as  that  is  the  time  when  the  plant  transpires 
most,  and  in  this  way  both  kinds  of  food  are  received 
together.  When  there  is  much  transpiration,  and  water 
containing  dissolved  food  is  pumped  up  rapidly,  then 
also  much  carbon  is  received,  and  vice  vend. 


172  Leaves  and  their   Work 

Such  plants  as  the  cactus,  which  have  no  leaves,  very 
few  pores,  and  skin  so  thick  and  leathery  that  evapora- 
tion is  prevented,  transpire  very  little,  and  grow  in 
consequence  very  slowly.  The  tall  Torch-thistle  cactus 
of  Mexico  is  said  to  take  some  hundreds  of  years  in 
attaining  its  full  size  ;  whereas  the  thin-leaved  gourd  of 
the  East  is  noted  for  its  very  rapid  growth. 

How  the  food  from  the  soil  and  the  food  from  the 
air  are  combined,  and  distributed  from  the  leaves  to  all 
parts  of  the  plant,  is  unknown ;  but  from  them  each 
part  does  receive  its  due  share  of  nourishment,  one 
more  of  this  sort,  one  more  of  that. 

But  without  the  leaves  no  food  can  be  prepared, 
except  where  the  stems  take  their  place ;  and  without 
light  the  leaves  have  no  power  to  act.  Hence  the 
plant's  whole  life  depends  upon  the  sun. 

In  the  autumn,  when  the  plant  has  finished  growing, 
no  more  leaf-green  is  formed,  and  the  leaves  begin  to 
change  colour ;  for  instead  of  manufacturing  food,  they 
are  giving  up  their  own  stock  to  feed  the  young  fruit. 

Some  plants,  such  as  lichens,  copper-beeches,  and 
others,  might  be  supposed  to  possess  no  leaf-green, 
because  it  is  not  visible ;  but  they  have  it  all  the  same ; 
it  is  merely  concealed  from  view,  hidden  by  other 
colouring  matter. 

But  some  plants  never  have  any  leaf-green  under  any 
circumstances,  and,  therefore,  being  non- manufacturers, 
they  have  to  live  by  the  labour  of  others.  Among 
these  are  the  fungi,  which  grow  and  feed  entirely  upon 
organic  matter,  animal  or  vegetable,  and  are  inde- 
pendent of  the  light.  Mushrooms,  for  instance,  may 
be  grown  in  cellars ;  toadstools  spring  up  in  the  night ; 
for  their  food  of  all  kinds — mineral  food,  nitrogenous 


Leaves  and  their  Work  173 

compounds,  carbon  compounds — has  been  made  ready 
for  them  in  the  light,  by  the  dead  vegetable  matter 
upon  which  they  grow.  Perhaps  it  is  the  fact  of  their 
not  having  any  work  to  do  which  enables  them  to  grow 
with  such  extraordinary  rapidity,  as  they  devote  all 
their  energies  to  feeding  and  increasing  in  size.  The 
cells  of  the  puff-ball,  for  instance,  multiply  at  the  rate 
of  three  or  four  hundred  million  in  an  hour,  and  the 
plant  will  attain  the  size  of  a  large  gourd  in  a  few  days. 
The  curious  brown  Bird's-nest  orchis  is  another  plant 
which  has  no  leaf-green,  cannot  provide  its  own  food, 
and  lives  upon  dead  vegetable  matter. 

But  there  are  other  plants  devoid  of  leaf-green,  which 
prey,  not  on  the  dead,  but  on  the  living ;  sucking  their 
juices,  and  profiting  by  their  labours  in  earth  and  air. 
Among  these  may  be  mentioned  the  broom-rape,  a 
brown,  uncanny-looking  plant,  which  attaches  itself  to 
the  roots  of  living  plants,  clover  and  others,  and  draws 
all  its  nourishment  from  them. 

In  one  way  or  another,  then,  all  plants  obtain  car- 
bon ;  and  when  they  have  to  do  it  by  their  own  exer- 
tions they  must  have  leaf-green,  and  they  cannot 
usually  have  leaf-green  without  light,  or,  in  any  case, 
without  iron. 

But,  it  may  be  said,  seeds,  most  of  them,  begin  to 
grow  in  darkness,  underground,  and  so  do  bulbs ;  and 
they  are  usually  pr.le  yellow  at  first.  If  they  have  no 
leaf-green,  as  they  evidently  have  not,  then,  if  cells 
cannot  be  multiplied  without  carbon,  and  carbon  they 
cannot  get  for  want  of  this  leaf-green,  how  do  they 
manage  to  grow  ? 

In  the  same  way  that  other  plants  do  which  are  also 
without  leaf-green.  They  make  use  of  the  carbon  stored 


174  Leaves  and  their  Work 

by  others.  That  is  to  say,  they  live  for  a  time,  seedlings 
— upon  the  material  stored  in  their  seeds — bulbs,  upon 
the  material  stored  in  the  bulbs,  which  are  buds,  not 
roots — all  of  which  has  been  prepared  by  means  of  leaf- 
green,  and  in  the  light. 

In  the  case  of  bulbs,  the  leaves  go  on  collecting  food 
long  after  the  plants  have  done  flowering,  in  readiness 
for  the  blossoms  of  the  next  spring ;  and  if  the  leaves 
are  cut  off  before  they  have  finished  their  work,  the 
bulbs  shrivel,  and  have  not  the  means  of  supplying 
next  year's  blossoms  at  all.  The  autumn  crocus  comes 
up  and  blossoms,  without  its  leaves,  but  it  is  dependent 
upon  them  for  the  means  of  putting  forth  its  blossoms  ; 
for  the  leaves  have  been  busy  months  before,  in  the 
spring,  storing  the  necessary  material  in  the  bulbs. 

Seedlings,  in  like  manner,  when  first  they  germinate 
under  the  soil,  before  they  are  provided  with  leaf- 
green,  live  upon  the  food  stored  up  within  them ;  but 
if,  when  this  is  exhausted,  they  are  still  kept  in  dark- 
ness, they  will  not  only  remain  yellow,  but  will  lose, 
instead  of  gaining  in  weight,  and  that  though  their 
roots  may  be  busy  collecting  food  from  the  soil. 

But  why,  it  may  be  asked,  should  they  lose  in  weight  ? 
Without  carbon  they  cannot,  of  course,  use  the  food 
from  the  soil,  they  cannot  grow ;  but  provided  they 
have  water,  why  should  they  not  remain  as  they  were  ? 
What  are  they  doing  to  make  them  lose  weight  ? 

Well,  they  are  doing  just  what  all  living  things  do, 
and  must  do,  if  they  are  to  remain  living ;  they  are 
breathing !  breathing  as  animals  do,  though  they  have 
no  lungs,  and  though  they  breathe  very  much  more 
slowly.  That  is  to  say,  they  are  taking  in  air. 

In  breathing,  as  has  been  said,  part  of  the  oxygen  of 


Leaves  and  their  Work  175 

the  air  inhaled  combines  with,  and  burns  up,  part  of 
the  carbon  taken  in  as  food,  converting  it  into  the  gas 
carbon-dioxide,  which  is  breathed  back  into  the  air. 
Warm-blooded  animals  breathe  much  more  vigorously 
than  plants  do,  but  the  process  is  the  same  in  both. 

Plants,  however,  breathe  more  or  less  through  their 
whole  surface,  though  chiefly  through  their  leaves,  and 
from  the  leaves,  the  air  finds  its  way  to  every  part. 

Probably  the  breathing  of  plants  may  be  fairly  com- 
pared with  the  slow  breathing  of  cold-blooded  animals  ; 
but  though  feeble  it  is  always  going  on,  night  and  day, 
in  light  and  in  darkness,  though  more  vigorously  in 
light ;  and,  therefore,  as  the  stock  of  carbon  is  gradu- 
ally burnt,  or  oxidized,  and  breathed  out,  if  it  is  not 
replenished  it  must  be  gradually  exhausted,  and  the 
plant  must  lose  weight. 

To  prove  this  two  beans  of  nearly  equal  weight  were 
planted  at  the  same  time,  one  being  kept  in  the  dark, 
the  other  in  the  light.  At  the  end  of  twenty-six  days  it 
was  found  that  the  seedling  kept  in  darkness  weighed 
more  than  a  third  less  than  the  original  bean,  and  the 
other  weighed  more  than  a  third  more.  The  one  had 
breathed  away  some  of  the  carbon  contained  in  the 
thick  seed-leaves  without  being  able  to  extract  any 
from  the  air  to  feed  upon,  while  the  other  had  obtained 
food  enough  for  growing  and  breathing,  too. 

There  is  some  difference  in  the  breathing  of  the 
leaves  and  the  blossoms  of  a  plant.  The  blossoms 
breathe  faster  than  the  leaves,  especially  when  they  are 
just  opening  ;  and  they  are  therefore  slightly  warmer — 
in  some  cases,  indeed,  so  warm  that  the  heat  may 
actually  be  felt !  And  the  same  is  true  of  sprouting 
seeds  when  there  are  many  together.  The  sprouting 


176  Leaves  and  their  Work 

barley,  for  instance,  from  which  malt  is  made,  gives  off 
quite  a  high  degree  of  heat. 

As  the  plant,  like  the  animal,  must  breathe  in  order 
to  live,  it  must  needs  have  a  constant  supply  of  air  for 
breathing,  as  well  as  feeding,  purposes.  And  this  air  is 
necessary,  more  or  less,  not  only  for  leaves  and  blos- 
soms, but  for  all  parts,  including  stems  and  roots.  It 
breathes  through  all,  though  chiefly  by  its  leaves  and 
blossoms ;  and  the  roots  are  always  breathing  out 
carbon-dioxide  into  the  soil.  If  the  soil  be  too  close, 
or  baked  on  the  top,  the  roots  cannot  get  enough  air  to 
breathe  properly,  and  the  plant  is  sickly.  And  the 
same  thing  happens  when  soil  is  piled  up  round  the 
stem,  for  the  air  is  then  kept  away  both  from  it  and 
from  the  roots,  and  many  a  tree  has  been  killed  in 
consequence. 

Leaves  covered  with  dust,  or  smoke-particles,  cannot 
possibly  thrive,  for  they  are  choked,  just  as  much  as  an 
animal  would  be  if  kept  without  air ;  and  besides  being 
unable  to  breathe,  they  are  also  unable  to  take  in  food. 
The  whole  plant,  therefore,  suffers,  and  unless  relief 
came  from  time  to  time  in  the  shape  of  rain  to  wash 
the  leaves,  it  must  die  of  suffocation. 

The  patient,  laborious  Chinese,  who  were  the  first  to 
attempt  market-gardening  in  the  sandy  environs  of 
Melbourne,  were  so  well  aware  of  the  fact  that  plants 
cannot  thrive  when  choked  with  dust  or  sand,  that  they 
were  in  the  habit  of  washing  their  vegetables,  leaf  by 
leaf,  three  times  every  day  to  keep  them  in  health. 


XIIL 

CLIMATE 

THE  plant's  whole  life  depends,  as  we  have  seen,  upon 
the  sun,  for  without  sunlight  it  cannot  obtain  carbon 
from  the  air  and  must  starve.  And  this  is  equally  true 
whether  the  plant  manufactures  its  own  food  or 
whether  it  feeds  upon  what  has  been  manufactured  by 
others.  The  parasite  sucks  the  juices  of  plants  growing 
in  the  light ;  the  fungus  feeds  upon  dead  vegetable 
matter  which  has  grown  in  the  light;  the  seedling 
lives  at  first  upon  food  stored  in  the  seed,  by  the  leaves 
which  waved  in  the  sunlight,  and  so  on. 

But  plants  require  of  the  sun  something  more  than 
light ;  they  must  have  some  degree  of  heat  as  well — a 
very  small  degree  in  some  cases,  but  this  small  degree 
is  essential  to  bring  them  to  maturity.  Even  those 
lowly  plants  which  grow  in  snow  and  ice  cannot  dis- 
pense with  some  amount  of  heat,  and  though  they 
contrive  to  exist  in  the  lowest  temperatures,  they 
remain  dormant  during  the  winter,  and  only  wake  up 
when  the  summer  sun  begins  to  shine. 

Many  seeds  will  even  begin  to  grow  while  it  is 
freezing,  though  they  cannot  make  much  progress ; 
and  wheat  has  been  known  to  germinate  when  actually 

12 


1 78  Climate 

upon  ice,  and  to  send  out  roots  into  it.  Barley  and 
oats  will  also  send  out  roots  with  the  thermometer 
down  to  freezing-point,  but  they  cannot  develop  seed- 
leaves  without  a  few  degrees  of  warmth.  Maize,  as 
might  be  expected,  requires  more  heat  than  any  other 
corn,  and  will  not  start  until  the  thermometer  shows 
about  15^°  above  freezing,  and  even  then  grows  but 
slowly;  and  cucumber-seed  shows  no  sign  of  life 
without  still  more  heat. 

But,  though  many  seeds  will  make  a  start  in  cold 
weather,  even  in  frost,  it  does  not  follow  that  they  will 
do  more  than  start;  for  a  plant  requires  different 
degrees  of  light  and  heat  at  different  times  in  its  life. 
And  if  it  does  not  receive  enough  at  the  important 
period  when  it  has  done  growing,  and  is  going  to 
blossom,  the  chances  are  that  it  will  bear  no  fruit. 
For  fruit  cannot  do  much  towards  feeding  itself,  and 
though  it  does  take  up  carbon  from  the  air,  it  is  chiefly 
dependent  for  nourishment  upon  the  leaves,  the  great 
food  manufacturers.  But,  in  a  cold  summer,  the  leaves, 
instead  of  passing  on  their  stock  of  food  to  the  fruit, 
and  themselves  turning  yellow,  as  they  ought  to  do, 
seem  to  be  quite  thrown  out  of  their  calculations.  They 
keep  their  food  to  themselves,  and  remain  green  and 
juicy,  while  the  fruit  is  starved,  and  its  development 
checked.  In  very  bad  cases,  the  plant  puts  out  new 
shoots,  and  the  crop  never  comes  to  perfection;  for 
the  heat  which  is  quite  sufficient  for  the  growth  of 
stems  and  leaves  is  not  sufficient  for  the  growth  and 
ripening  of  the  fruit. 

If,  on  the  other  hand,  the  piant  gets  too  much  ligftt 
and  heat  at  an  early  stage  in  its  life,  it  grows  up  and 
ripens  its  fruit  too  quickly,  before  it  is  properly 


Climate  179 

developed;  and  this  is  what  takes  place  when  crops 
are  sown  too  late  in  the  year.  In  the  ordinary  course 
of  nature,  seed  generally  drops  and  sows  itself  as  soon 
as  it  is  ripe,  and  begins  to  grow  forthwith.  But  it 
cannot  go  on  growing.  Winter  comes  and  checks  it, 
and  it  is  obliged  to  put  off  bearing  fruit  till  the  following 
summer.  Plants  grown  in  this,  the  natural  way,  are 
generally  the  stronger,  if  they  manage  to  survive  the 
winter.  But  they  are  exposed  to  more  perils  than 
when  the  seed  is  sown  in  spring,  and  of  course  they 
are  much  longer  in  coming  to  perfection. 

Barley  sown  early  in  August  and  September,  as  soon 
as  it  is  ripe,  has  been  found  to  take  two  hundred,  and 
two  hundred  and  forty  days,  to  come  to  perfection, 
which  is  just  eight  times  as  long  as  it  often  does  in 
Egypt,  where  it  is  sown  and  ripened  not  only  the  same 
year,  but  quite  early  in  the  year. 

Provided,  however,  the  seed  be  not  sown  too  late, 
the  crop  seems  to  be  equally  good  whether  the  seed  be 
sown  in  autumn  or  spring.  Barley  sown  for  experiment 
on  the  2ist  of  April  came  to  perfection  in  eighty-eight 
days,  that  is,  by  the  i8th  of  July ;  whereas  that  sown 
five  weeks  later  ripened,  indeed,  in  an  equal  number 
of  days,  but  prematurely,  before  the  grain  was  properly 
developed,  because  it  had  been  over-stimulated — too 
much  hurried,  in  fact,  during  the  long,  light,  warm 
days  of  June. 

Of  all  the  influences  by  which  the  plant  is  surrounded, 
none  affect  it  so  powerfully,  for  good  or  evil,  as  light, 
temperature  and  moisture,  or,  in  one  word,  climate. 
Where  the  climate  is  favourable,  the  quality  and 
quantity  of  the  soil  are  of  comparatively  little  import- 
ance, for  the  plant  manages  to  make  the  very  utmost 


i8o  Climate 

of  what  it  has.  But,  where  the  climate  is  unfavour- 
able, no  soil,  however  good  and  abundant,  can  make 
up  for  it,  though  it  may  do  something  to  lessen  the 
evil  consequences. 

As  we  have  already  seen,  the  richest  soil  is  unable 
to  supply  the  place  of  water ;  while  in  Guiana,  on  the 
other  hand,  where  moisture  is  abundant,  and  the 
climate  genial,  groups  of  trees  may  be  seen  growing  on 
a  spur  of  the  great  sandstone  mountains,  wherever 
there  is  just  sand  enough  to  afford  them  a  foothold. 
The  sand  is,  of  course,  not  mere  sand,  though  it  may 
look  like  it ;  but  the  soil  is  undeniably  poor  and 
shallow.  Yet,  helped  by  the  climate,  the  trees  thrive, 
as  they  could  not  possibly  do  without  that  help. 

We  are  naturally  accustomed  to  look  upon  the  sun 
as  the  source  of  light  and  heat  to  our  planet;  but 
temperature  does  not  depend  solely  upon  the  sun  ;  for 
if  it  did,  the  same  temperature  would  prevail  all  along 
the  same  parallel  of  latitude,  which  it  certainly  does  not. 

Rhine  grapes,  for  instance,  will  not  ripen  in  England ; 
laurels  and  camellias  flourish  all  the  year  round  on  the 
coast  of  Cornwall,  while  in  the  same  latitude  on  the 
continent,  only  the  hardiest  trees  can  stand  the 
winter.  The  vine  can  hardly  flourish  at  the  mouth  of 
the  Loire ;  yet  it  comes  to  perfection  in  Tokay,  which 
lies  a  degree  further  to  the  north ;  and  Astrakhan,  in 
nearly  the  same  latitude,  has  summer-heat  enough  to 
ripen  the  southern  fruits  of  Italy,  and  even  of  the 
Canary  Islands,  though  its  winters  are  so  severe  that 
no  vine-stock  would  be  able  to  live  through  them 
without  being  buried  several  feet  deep  in  earth. 

In  Germany,  where  the  summers  are  much  hotter 
than  in  England,  roses,  and  other  trees  and  shrubsf 


Climate  181 

which  we  do  not  think  of  protecting,  are  matted  up 
like  mummies  for  the  winter. 

Then  again,  myrtles  will  flourish  out  of  doors  all  the 
year  round  in  Ireland,  as  well  as  they  do  in  Portugal ; 
but  plums  and  pears  do  not  usually  ripen  well,  though 
they  will  do  so  perfectly  on  the  continent,  in  the  same 
latitude. 

It  is  evident,  therefore,  that  the  climate  of  a  country 
does  not  depend  solely  upon  its  position  with  regard 
to  the  equator.  Indeed,  the  great  characteristic  of  the 
equatorial  climate  is,  not  so  much  its  heat,  as  its 
wonderful  uniformity.  Hot  it  is,  of  course,  though 
not  as  hot  as  the  plains  of  North  India ;  but  there  is 
nothing  to  be  called  change  of  season,  and  there  is 
seldom  more  than  16°  or  17°  of  difference  between  day 
and  night.  It  is  not  often  that  the  thermometer  stands 
above  90°  or  91°  F.  by  day,  or  falls  below  74°  F.  by 
night.  And  the  temperature  of  the  soil  varies  but 
little,  too.  Four  or  five  feet  below  the  surface  it  never 
varies  at  all,  and  remains  constantly  at  80°  F.,  just 
about  half-way  between  the  temperature  of  night  and 
day. 

Where  the  temperature  of  the  air  varies  more,  there 
the  temperature  of  the  soil  varies  more  also,  and  to  a 
greater  depth.  At  the  equator,  the  sun  affects  only 
the  upper  four  or  five  feet  of  the  soil,  the  change 
between  day  and  night  being  unfelt  below  this ;  but  in 
England  the  change  between  summer  and  winter  is 
felt  to  a  depth  of  fifty  or  sixty  feet  probably  ;  and  below 
this  the  temperature  remains  steady  at  but  a  little 
above  40°  F. 

40°  F.  is  about  the  mean  temperature  of  the  air  in 
England,  a.s  80°  F.  is  that  of  the  equatorial  region — 


1 82  Climate 

half-way  between  the  two  extreme  points  to  which  the 
thermometer  rises  and  falls. 

But  this  fact,  that  the  depth  at  which  the  tempera- 
ture of  the  soil  remains  always  the  same  is  so  much 
greater  in  one  case  than  in  the  other,  has  much  influ- 
ence upon  the  two  climates ;  and  for  this  reason : 
whenever  a  hot  body  is  in  contact  with  a  cold,  or  cooler 
one,  it  at  once  gives  up  some  of  its  heat  to  this  other, 
and  continues  to  do  so  until  there  is  no  difference  be- 
tween the  two. 

When,  therefore,  the  sun  warms  the  surface  of  the 
soil,  the  upper  layer  parts  with  some  of  its  heat  to  the 
one  below  it,  this  to  the  next  below,  and  so  on,  until 
that  depth  is  reached  where  the  temperature  is  always 
the  same.  At  the  equator,  therefore,  the  heat,  having 
only  four  or  five  feet  of  soil  to  travel  through,  soon 
raises  the  temperature  of  the  whole  mass  equally,  and 
then,  as  it  cannot  descend  any  lower,  it  goes  on  adding 
to  the  heat  of  these  upper  layers,  in  which  it  accumu- 
lates. At  night,  when  the  sun  is  gone,  the  surface  of 
the  soil  cools,  and  the  reverse  process  begins  :  the  heat 
stored  during  the  day  gradually  passes  up  again  to  the 
surface,  and  from  the  surface  into  the  air,  so  that  both 
earth  and  air  are  kept  at  a  more  even  temperature  than 
would  otherwise  be  the  case. 

But  where,  as  in  England,  the  sun  has  forty  or  fifty 
feet  of  cool  earth  to  warm,  naturally  it  is  much  longer 
about  it,  and  the  whole  mass  is  consequently  not 
warmed  equally  through  till  summer  is  at  its  height. 
Then,  and  not  till  then,  the  whole  mass  being  warm, 
heat  begins  to  be  stored  during  the  day  in  the  upper 
layers,  and  is  given  up  again,  when  the  sun  is  down,  to 
warm  the  air  at  night.  Hence  we  have  warm  nights  in 


Climate  183 

July  and  August ;  and  winter  is  less  cold  than  it  would 
otherwise  be,  thanks  to  the  heat  gradually  given  back 
by  the  great  mass  of  earth. 

But  the  heat  given  back  to  the  air  in  this  way  would 
quickly  escape,  and  benefit  us  little,  were  it  not  for  the 
moisture  in  the  air,  which  acts  the  part  of  a  blanket, 
and  keeps  it  near  the  earth.  At  the.  equator,  the  air  is 
generally  in  a  very  moist  condition  all  the  year  round  ; 
and  this  moisture,  while  serving  the  part  of  a  blanket 
by  night,  acts  as  a  veil  or  parasol  by  day,  and  prevents 
the  sun's  rays  from  being  too  scorching. 

It  is  to  the  large  quantity  of  moisture  in  the  air  that 
the  region  of  the  equator  owes  its  very  even  tempera- 
ture, therefore. 

In  the  dry  plains  of  North  India  the  heat  is  scorch- 
ing, much  greater  than  at  the  equator,  just  for  want 
of  this  veil ;  and  the  nights  are  often  so  cold  that  water 
is  frozen,  because  the  heat  received  by  day  all  escapes 
again  through  the  clear  air. 

Everybody  knows  that  a  clear  night  is  a  cold  night, 
while  a  misty  or  cloudy  one  is  comparatively  warm. 

Among  other  circumstances,  therefore,  which  greatly 
affect  the  climate  of  a  country  is  its  nearness  to  or  dis- 
tance from  the  ocean.  For  where  constant  evaporation 
is  going  on,  on  a  large  scale,  as,  of  course,  it  is  from 
the  ocean,  there  the  air  must  needs  be  loaded  with 
moisture,  with  the  consequences  already  mentioned  : 
the  nights  are  warmer,  the  days  cooler,  the  winters  less 
severe,  the  summers  less  scorching.  In  one  word,  the 
climate  is  more  equable.  Moreover,  the  ocean  is 
warmer  than  the  land,  in  winter  and  by  night,  while 
it  is  cooler,  in  summer  and  by  day ;  and  this  tends  to 
further  equalize  the  temperature. 


184  Climate 

Winters  are  colder  and  summers  hotter  in  Germany 
than  in  England,  mainly  for  this  reason — because  the 
air  is  so  much  drier  owing  to  the  greater  distance  of 
the  ocean.  For  the  same  reason,  plants  and  shrubs 
need  protection  there  during  the  winter  which  they  do 
not  here  ;  and,  on  the  other  hand,  grapes  will  ripen 
there  when  they  will  not  here. 

But,  besides  these  general  circumstances,  there  are 
also  various  local  circumstances  which  affect  climate 
more  or  less.  Thus,  if  the  neighbourhood  of  the  ocean 
tends  to  equalize  climate,  the  neighbourhood  of  any 
large  expanse  of  dry  soil  does  exactly  the  reverse,  inas- 
much as  it  dries  the  air. 

If  the  Sahara  were  covered  with  water,  the  climate 
of  the  South  of  Europe  would  be  many  degrees  less 
warm  than  it  is ;  for  the  wind  passing  over  it  would  be 
cooled,  instead  of  heated  as  it  now  is.  It  would  also  be 
moistened,  and  so  more  snow  would  fall  in  the  Alps, 
and  less  would  melt  in  the  summer. 

Then,  again,  there  are  the  many  ocean  currents,  hot 
and  cold,  which  also  influence  climate  to  a  considerable 
extent.  Western  Europe  would  be  far  colder  than  it 
is  without  the  Gulf  Stream,  which  brings  about  166,000 
cubic  miles  of  hot  water  from  the  tropics  to  the  North 
Atlantic  in  the  course  of  each  year.  And  this  tre- 
mendous volume  of  steaming  water,  besides  warming 
the  air,  loads  it  with  moisture ;  so  that  it  is  easy  to 
understand  why  the  winter  climate  of  Ireland  should 
be  mild  enough  to  allow  of  myrtles  flourishing  out  of 
doors,  and  yet  why  the  summer  heat  should  not  be 
sufficient  to  ripen  fruit,  owing  to  the  thick  veil  of 
vapour  which  screens  it  from  the  sun. 

Other  local  circumstances  which  affect  climate  in  a 


Climate  185 

greater  or  less  degree  are  the  presence  of  forests, 
rivers,  lakes,  mountains,  which  cannot  now  be  dealt 
with  in  detail. 

But  plants  are  also  affected  in  a  minor  degree  by  the 
colour  of  the  soils  in  which  they  grow. 

Dark  substances  absorb  more  heat  than  light  ones 
do  ;  and  snow  will  melt  more  quickly  if  a  piece  of  black 
cloth  be  stretched  above  it,  even  though  the  two  do 
not  touch  one  another.  In  the  Arctic  regions  the  ice 
melts  much  faster  wherever  a  small  dark-brown  plant, 
of  the  same  family  as  the  Red  Snow,  grows,  because  it 
attracts  the  heat.  So,  too,  in  some  parts  of  Switzer- 
land the  peasants  hasten  the  departure  of  the  snow  by 
strewing  it  with  black  powdered  slate. 

Dark  soils  are  therefore  usually  warmer  than  light 
ones  ;  and  it  is  not  an  uncommon  thing  for  gardeners 
to  sprinkle  a  light-coloured  soil  with  peat,  charcoal,  or 
vegetable  mould  to  warm  it,  for  these  all  act  as  sun- 
traps. 

Melons  are  thus  ripened,  even  in  the  coolest  summers, 
at  Freiberg,  in  Saxony,  by  means  of  a  layer  of  coal- 
dust. 

Grapes,  too,  in  the  Rhine  district,  ripen  best  where 
the  ground  is  covered  with  fragments  of  black  slate; 
and  the  vines  are  purposely  kept  near  the  ground,  that 
they  may  have  the  full  benefit  of  the  heat  which  the 
slate  absorbs  by  day  and  gives  up  again  by  night. 

The  difference  in  temperature  between  two  sub- 
stances, one  of  which  is  white  and  the  other  black, 
when  both  are  equally  exposed  to  the  sun,  is  very  re- 
markable. There  will  be  as  much  as  thirteen  or  fourteen 
degrees  difference,  for  instance,  in  the  temperatures  of 
a  piece  of  lamp-black  and  of  a  pie  e  of  magnesia. 


i  #6  Climate 

But  though  colour  makes  such  an  important  differ- 
ence in  the  power  to  absorb  heat,  it  has  no  influence, 
apparently,  upon  the  power  to  retain  it.  Indeed, 
though  sand  may  absorb  heat  less  quickly  than  a 
darker  soil  does,  when  once  it  is  warm  it  remains  warm 
longer  than  any  other.  The  coarser  it  is,  too,  the  less 
quickly  it  cools  ;  and  as  coarse  gravel,  once  thoroughly 
heated,  retains  some  degree  of  heat  even  through  the 
night,  it  is  found  useful  to  put  it  round  grape-vines  to 
keep  them  warm. 

Great,  and  especially  sudden,  changes  of  temperature 
are  particularly  trying  to  most  plants,  though  such  as 
grow  in  deserts  have  become  so  accustomed  to  being 
scorched  by  day  and  frozen  by  night,  as  at  least  to 
manage  to  keep  alive.  But  though  an  even  tempera- 
ture is  in  some  ways  most  desirable,  it  does  not  by  any 
means  follow  that  all  plants  would  thrive  in  the  equa- 
torial region.  That  region,  as  has  been  said,  is  charac- 
terized less  by  its  great  heat  than  by  its  remarkable 
uniformity  of  climate.  It  knows  no  change  of  seasons : 
it  is  always  summer,  always  spring,  and  always  autumn 
there,  and  many  trees  bear  both  flowers  and  fruit  at 
the  same  time.  But  this  constant  activity,  though  it 
suits  the  trees  and  plants  accustomed  to  it,  is  too 
much  for  our  European  fruit-trees  and  other  plants; 
for  these  are  in  the  habit  of  taking  a  winter  sleep,  and 
cannot  get  on  without  it.  Transported  to  the  equa- 
torial region,  they  grow,  indeed,  freely  enough,  but  too 
freely;  for  they  become  evergreen,  putting  out  fresh 
leaves  all  the  year  round,  and  are  so  exhausted  for 
want  of  their  customary  rest  that  they  are  unable  to 
ripen  their  fruit.  This  is  the  case  even  when  they  are 
taken  to  the  cooler  hill-country  of  Ceylon ;  and  it  is 


Climate  187 

true  even  with  regard  to  the  vine,  which,  though  a 
native  of  warm  climates,  still  is  not  a  tropical  plant, 
and  is  accustomed  to  shed  its  leaves  year  by  year.  In 
the  tropics,  however,  its  leaves  remain  green,  instead 
of  giving  up  their  stores  to  feed  the  fruit  as  they  ought ; 
the  grapes  fall  off  almost  unformed,  and  the  vine  puts 
all  its  energy  into  growing  leaves  instead  of  fruit,  not 
having  strength  for  both.  The  one  thing  which  it  lacks 
is  rest — the  rest  which  in  winter  it  is  compelled  to 
take. 

It  being,  however,  impossible  to  provide  the  vines 
with  winter-cold  in  Ceylon,  it  was  suggested  that  heat 
might  perhaps  be  made  to  answer  the  purpose  as  well, 
and  the  experiment  was  tried  of  laying  the  roots  bare 
for  a  time  to  the  strongest  sun.  This  had  the  effect  of 
checking  the  flow  of  sap  as  effectually  as  frost  could 
have  done :  the  leaves  dropped,  the  vines  had  their 
sleep,  and  awoke  from  it  so  refreshed  and  invigorated 
that  they  were  able  to  bring  their  crop  to  maturity; 
and  this  plan  has  been  adopted  with  success  both  in 
Ceylon  and  Bombay. 

In  those  tropical  regions,  outside  the  equatorial  belt, 
where  there  are  periodical  rainy  seasons  and  long 
droughts,  the  latter  answer  all  the  purpose  of  winter, 
and  are,  indeed,  winter,  so  far  as  vegetation  is  con- 
cerned, in  spite  of  their  intense  heat.  Trees  and  shrubs 
are  as  leafless  in  the  desert  of  Nubia,  for  instance, 
before  the  rains  set  in,  as  if  it  were  mid-winter,  in  spite 
of,  or,  rather,  in  consequence  of,  the  terrible  heat ;  and 
thus  a  time  of  rest  is  secured  to  them. 

In  the  far  north  we  have  a  very  different  state  of 
things.  Here,  instead  of  its  being  necessary  to  secure 
that  the  plants  shall  have  rest,  the  great  thing  is  to 


1 88  Climate 

provide  that  they  shall  make  the  utmost  of  the  very 
short  spring  and  summer  which  are  all  that  fall  to  their 
lot.  Their  time  of  sleep  lasts  on  an  average  ten 
months,  and  during  the  remaining  two  months  they 
have  everything  to  do,  so  that  it  is  most  necessary  that 
they  should  make  the  most  of  their  time.  The  days 
are  of  course  very  long,  which  is  a  help,  while  the 
nights  are  so  light  as  to  be  hardly  like  night ;  and  if 
Professor  Nordenskjold's  observations  be  trustworthy, 
it  seems  that  the  plants  do  indeed  turn  every  moment 
to  account,  by  growing  all  night  as  well  as  all  day. 

But  many  of  them  do  a  great  deal  of  growing  in 
advance,  so  that  as  soon  as  the  summer  comes  their 
blossoms  and  fruit,  which  need  heat  more  than  the 
leaves,  may  be  ready  at  once  to  take  advantage  of  it. 
These  plants,  that  is  to  say,  make  very  large,  strong 
buds,  which  are  packed  full  of  leaves  and  blossoms  in  a 
more  or  less  undeveloped  state,  but  with  all  their  parts 
ready,  before  the  winter  sets  in.  Directly  the  growing 
time  comes  round  again,  therefore,  they  can  burst  out, 
and  begin  to  gather  food  from  the  air  at  once,  and  the 
plant  is  able  to  blossom  very  early,  thus  ensuring  as 
much  time  as  possible  for  the  perfecting  of  the  fruit. 

Most  of  the  plants  ripen  their  fruit,  but  some  few  are 
not  able  to  do  so,  except  now  and  then,  when  the 
summer  is  hotter  or  longer  than  usual ;  and  some  which 
are  annuals  further  south  become  perennials  here,  as 
they  would  not  have  time  to  grow  from  seed,  and  ripen 
seed,  in  one  short  season. 

During  the  long  winter  many  are  of  course  protected 
by  the  snow;  but  there  are  wide  surfaces  here  and 
there  left  quite  bare  of  covering,  and  yet  even  here 
plants  manage  to  survive,  some  without  any  protection 


Climate  189 

whatever,  others  because  they  are  buried  under  a  deep 
layer  of  dead  leaves  and  stems. 

But  though  they  bear  the  intense  cold  without 
injury,  it  is  quite  evident  that  even  these  dwellers  in 
the  Arctic  regions  enjoy  a  little  warmth  when  they  can 
get  it,  for  they  are  most  abundant  on  sunny  slopes  and 
in  sheltered  nooks  and  corners.  Many  of  them,  indeed, 
crouch  close  to  the  ground,  and  few  venture  to  raise 
their  heads  very  high ;  trees  there  are  none,  the  bushes 
are  dwarfs,  with  few  and  small  leaves,  and  the  vegetation 
generally  is  on  a  miniature  scale.  Still,  there  is  vege- 
tation ;  and  whether  in  *  deserts  '  of  ice  or  '  deserts '  of 
sand,  it  would  be  equally  difficult  to  find  any  spaces  of 
large  extent  where  vegetable  life  of  some  kind  or  other 
does  not  exist,  at  least  during  certain  seasons  of  the 
year. 


XIV. 

BLOSSOM   AND   SEED 

PLANTS,  even  the  very  humblest  and  lowliest,  have,  as 
we  have  seen,  many  requirements  in  the  way  of  food  of 
various  kinds,  water,  air,  light,  and  warmth.  But 
having  seen  them  duly  provided  with  all  these,  we 
might  fancy  that  now  at  last  all  their  wants  were 
satisfied,  and  that  nothing  more  remained  but  for  them 
to  make  the  best  of  their  opportunities  and — grow. 

But  all  depends  upon  what  we  consider  to  be  the 
plant's  object  in  life.  For  instance,  we  may  be  quite 
satisfied  to  grow  orange-trees  for  their  blossom  merely, 
or  maize  for  use  as  forage,  and  palms  for  the  sake  of 
their  foliage,  in  climates  where  it  is  impossible  for  any 
one  of  them  to  ripen  their  fruit.  And  provided  they 
throve  and  answered  these  purposes,  our  object  would 
be  attained. 

But  plants  in  the  natural  state  grow  to  bear  and 
ripen  fruit.  All  the  rest  of  their  lives  is  merely  a  pre- 
paration for  this  one  grand  end.  The  roots  draw  food 
from  the  soil,  and  the  leaves  do  the  same  from  the  air, 
all  for  the  purpose  of  feeding  and  maturing  the  fruit — 
the  one  aim  to  which  everything  tends. 

Of  course,  where  man  comes  upon  the  scene  it  is 


Blossom  and  Seed  191 

quite  another  matter,  as  he  can  take  cuttings  of  some, 
divide  the  roots  of  others,  and  fetch  continual  supplies 
of  seed  from  the  ends  of  the  earth,  if  necessary.  But 
the  wild  plant  has  not  these  resources  to  fall  back  upon, 
and  if  its  race  is  to  continue,  it  must  as  a  rule  be  able 
to  perfect  its  seed,  otherwise  it  will  merely  thrive  for  a 
time,  longer  or  shorter,  according  as  it  is  an  annual 
or  a  perennial,  and  then  it  will  perish  without 
descendants. 

But  in  very  many  cases  the  plant,  like  Mr.  Belt's 
scarlet-runners  already  mentioned,  is  quite  unable  to 
perfect  seed  without  the  help  of  what  we  may  call 
nature's  under-gardeners.  The  plant  does  much  for  its 
offspring ;  it  collects  and  stores  food,  it  drains  itself 
of  its  own  life-juices  for  their  benefit,  but  it  cannot 
always  do  everything ;  and  if  these  under-gardeners 
were  banished  from  the  earth,  some  plants  would 
speedily  vanish  also. 

Both  blossoming  and  fruit-bearing  are  processes  more 
or  less  exhausting  to  the  plant,  for  neither  flowers  nor 
fruits  do  much,  though  they  do  something,  towards 
feeding  themselves.  Annuals  blossom  and  bear  fruit 
once  and  then  die  entirely,  roots  and  all,  their  leaves 
and  stems  being  drained  of  nourishment  by  the  end  of 
the  season.  Others,  perennials,  die  down,  but  their 
roots  remain  alive ;  and  others  again,  merely  shed 
their  exhausted  leaves,  and  grow  fresh  ones,  for  several 
or  many  seasons  in  succession.  Others  again,  take 
more  than  one  season  to  store  food  before  they  venture 
upon  the  expense  of  having  blossoms  at  all ;  and  others 
take  many  years  to  prepare  for  this  great  effort,  and 
when  it  is  at  last  accomplished,  the  great  end  of  their 
lives,  they  die  of  mere  exhaustion. 


1 92  Blossom  and  Seed 

The  food  of  blossom  and  fruit  is,  as  has  been  said, 
very  generally  accumulated  in  the  leaves  and  stems  of 
the  plant ;  but  sometimes  the  root  serves  as  the  main 
storehouse.  The  turnip,  for  instance,  like  other 
biennials,  spends  the  first  year  of  its  life  in  doing 
nothing  but  gather  a  store  of  food  by  means  of  its  roots 
and  its  tuft  of  leaves.  It  does  not  shoot  up,  and  it 
makes  no  attempt  to  blossom  ;  and  as  the  farmer  does 
not  want  turnip-blossom,  and  does  want  roots,  he  takes 
the  latter  while  they  are  plump,  and  well-filled  with  the 
food  intended  for  the  seed.  If  he  waited  till  the  next 
year  he  would  see  his  turnip-plants  shoot  up  rapidly 
and  blossom ;  and  very  thriving  they  would  look,  no 
doubt ;  but  all  this  time  they  would  be  sucking  away  at 
the  roots,  which  would  be  losing  their  plumpness,  and 
growing  gradually  hollower  and  more  hollow,  until,  by 
the  end  of  the  second  year,  they  would  be  reduced  to 
nothing  but  fibre,  and  be  quite  useless. 

We  have  spoken  already  of  bulbous  plants,  such  as 
crocuses,  whose  blossoms  are  nourished  on  the  food 
previously  stored  for  them  in  the  bulb,  by  the  leaves, 
which,  in  most  cases, '  do  the  chief  part  of  their  work 
after  the  blossoms  have  faded.  But  in  some  instances, 
as  in  that  of  the  colchicum,  or  meadow  saffron,  they 
come  up  and  make  their  preparations  in  the  spring, 
for  the  blossoms  which  do  not  appear  till  the  autumn, 
long  after  the  leaves  have  vanished.  In  these  cases 
the  food  for  the  blossoms  is  stored  in  the  bulbs; 
and  if  a  tidy  gardener  unwarily  cuts  off  the  leaves 
before  the  bulb  is  properly  stocked,  he  starves  the 
blossoms. 

But  some  plants  take  years  to  prepare  food  sufficient 
for  the  supreme  effort  of  their  lives. 


Blossom  and  Seed  193 

The  American  aloe,  for  instance,  which  was  sup- 
posed to  blossom  only  once  in  a  hundred  years,  though 
it  does  not  wait  quite  so  long  as  this,  does  actually 
wait  five  or  six  years  in  its  own  country,  and  from  fifty 
to  seventy  in  ours,  before  it  attempts  to  send  up  a 
flower-spike.  But  when  it  does  begin,  it  grows  with 
such  tremendous  energy — at  the  rate  of  a  foot  a  day 
even  in  our  conservatories — that  one  can  well  under- 
stand its  need  of  a  large  store  of  food  ready  for  im- 
mediate use,  since  it  would  be  impossible  for  leaves 
and  roots  to  collect,  manufacture,  and  supply  it  as  fast 
as  it  is  wanted. 

The  aloe  does  not,  however,  always  die  of  its  effort, 
and  may  live  to  blossom  again,  some  years  later ;  but 
the  Talipot  palm,  though  it  attains  a  great  age,  spends 
its  whole  life  in  accumulating  food  for  its  progeny; 
and  having  once  blossomed,  it  is  quite  exhausted  and 
perishes. 

Blossoming,  then,  is  a  serious  matter  for  all  plants, 
and  not  to  be  undertaken  without  due  preparation. 
But  it  is  a  curious  fact  that  the  size  of  a  plant's  blos- 
soms is  often  quite  independent  of  the  size  of  the  plant 
itself.  Many  a  forest-tree,  for  instance,  bears  flowers 
which  are  quite  minute  and  insignificant ;  others,  as 
some  of  the  palms,  bear  spikes  of  blossom  several  feet 
in  length  and  leaves  in  proportion.  As  a  rule,  how- 
ever, trees  have  small  leaves,  small  dull  blossoms,  and 
small  seeds  for  their  size ;  but  they  bear  all  three  in 
large  numbers.  A  diminutive  cactus,  only  a  few  inches 
high,  on  the  other  hand,  may  boast  a  glorious  crimson 
flower,  measuring  two  or  three  inches  across;  but, 
then,  it  has  to  be  satisfied  with  one  or  perhaps  two. 
The  beautiful  night-flowering  cactus  attains  some  size, 

13 


194  Blossom  and  Seed 

but  it  is  a  conservatory  plant,  not  a  tree,  yet  its  blos- 
soms measure  half  a  foot  across  and  it  bears  at  times 
as  many  as  twenty  or  thirty  together. 

The  largest  known  blossom,  however,  is  that  of  the 
extraordinary  Rafflesia  Arnoldi,  a  native  of  Java  and 
Sumatra,  which,  much  more  truly  than  even  the  orchids, 
is  'all  blossom,'  for  it  has  neither  branches,  leaves,  nor 
roots.  Of  course,  therefore,  it  must  needs  be  a  parasite, 
living  by  and  sucking  the  life-juices  from  others  ;  and 
it  produces  a  huge  blossom,  more  than  a  yard  across, 
mainly  at  the  expense  of  the  vine -like  plant  upon 
which  it  fixes  itself. 

It  is  not  by  any  means  a  beautiful  object,  and  its 
petals,  which  are  thick  and  fleshy  in  texture  as  well  as 
flesh-coloured,  have  the  smell  of  tainted  beef.  This 
monster  takes  several  months  to  come  to  perfection, 
and  then  weighs  about  fifteen  pounds ;  after  which  it 
begins,  in  a  few  days,  to  wither  away. 

An  ordinary,  complete,  simple  blossom,  whether 
large  or  small,  brightly  coloured  or  inconspicuous,  con- 
sists of  two  sets  of  parts,  or  organs,  an  outer  and  an 
inner  set.  It  is  the  function  of  the  inner  set  to  form 
the  seed  ;  and  it  is  the  function  of  the  outer  set  to 
protect  the  inner  from  all  injury,  and  also,  in  many 
cases,  to  attract  the  under-gardeners  already  referred 
to,  whose  good  offices  are  required  for  the  development 
of  the  seed. 

The  perfecting  of  the  seed  is  the  great  thing  to  be 
accomplished  ;  and  those  parts  of  the  blossom  which 
contribute  to  this  object  are  placed  in  the  centre,  as 
far  out  of  harm's  way  as  possible.  If  we  examine,  for 
instance,  a  common  primrose,  splitting  it  carefully 


Blossom  and  Seed  195 

upwards  from  the  base  of  the  flower,  we  shall  see  in 
the  very  centre  a  hair-like  stalk,  with  a  knob  at  the 
upper  end  and  a  hollow  swelling  at  the  lower  end.  On 
splitting  open  this  hollow  part,  we  find  that  it  contains 
a  number  of  very  minute  grains,  ovules,  or  little  eggs, 
which,  in  the  ordinary  course  of  things,  would  be  con- 
verted into  seeds. 

This  central  organ  is  the  pistil,  which  consists  of 


Section  of  Fuchsia-blossom. 

one  or  more  bodies,  named  carpels,  each  with  its 
hollow  case,  or  ovary,  below,  and  its  stalk,  or  style, 
above ;  and  these  are  either  distinct  one  from  another, 
or  combined  into  one  organ. 

Outside  the  pistil  stand  the  dust-spikes,  or  stamens, 
— stalks  bearing  each  a  double  sac,  or  anther,  which 
is  filled  with  the  dust  known  as  pollen.  Pistil  and 


196  Blossom  and  Seed 

stamens  together  form  the  inner  and  more  important 
set  of  organs. 

The  outer  set  consists  of  a  double  envelope  of  leaves; 
the  inner,  or  petals,  more  delicate  in  texture  and  more 
varied  in  colour,  forming  the  corolla;  and  the  outer, 
or  sepals,  generally  green,  and  forming  the  calyx.  A 
perfect  flower  has  all  these  parts,  and  some  have 
double  rows  of  each.  Naturally  our  eye  is  attracted 
chiefly  by  the  brightly  coloured  part  of  a  blossom,  and 
we  think  little  about  the  inner  organs,  which  are  often 
almost  or  quite  hidden  from  our  sight.  But  it  is 
these  inner  organs  which  are  really  the  only  absolutely 
necessary  parts  of  a  blossom. 

Many  flowers  have  no  calyx  at  all ;  some  have  no 
petals  ;  but,  provided  they  have  stamens  and  pistil,  they 
can  still  accomplish  all  that  is  necessary  for  the  perfect- 
ing of  their  seed.  Even  pistil  and  stamens,  however, 
may  be,  and  often  are,  reduced  in  size  and  deprived  of 
their  stalks  ;  but  dust-cells  there  must  be,  and  ovules, 
or  grains  to  be  developed  into  seeds,  there  must  be  if 
the  plant  is  to  bear  seed  at  all. 

Now  all  these  organs,  the  inner  set  as  well  as  the 
outer  set,  are  really  leaves — leaves  whose  appearance 
and  duties  in  life  have  been  altered.  The  calyx  still 
looks  more  or  less  leaf-like  usually,  and  it  is  not 
difficult  to  believe  that  the  petals  might  be  leaves  too, 
though  more  delicate  and  more  daintily  coloured.  But 
it  is  less  easy  to  believe  the  same  of  stamens  and 
pistil.  Let  us,  however,  look  for  them  in  any  double 
blossom,  and  we  shall  find  few  if  any,  for  they  have 
been  changed  into  petals.  It  is  blossoms  with  many 
stamens,  such  as  the  rose,  ranunculus,  anemone  ;  or 
blossoms  with  many  florets,  such  as  the  daisy  and 


Stossom  ancC  Seed  197 

dahlia,  which  are  most  commonly  doubled  by  cultiva- 
tion. 

Nature  does  not  grow  many  double  flowers,  for 
wild  plants  need  seed,  and  double  flowers  produce  little 
if  any,  seed  being  sacrificed  to  petals.  Geraniums, 
which  have  only  ten  stamens,  are  among  the  plants, 
however,  which  have  a  tendency  to  increase  the 
number  of  their  petals;  and,  among  the  single  blossoms, 
one  may  often  be  seen  with  a  petal  or  two  more  than 
the  rest,  or  an  extra  small  petal,  which  is  half  way 
between  a  petal  and  a  stamen.  If  the  seed  from  this 
blossom  were  saved,  some  of  the  next  generation  of 
plants  might  have  still  more  petals  and  still  fewer 


Pollen  of  the  Melon,  magnified. 

stamens,  and  by  carefully  cultivating  those  having 
these  peculiarities  the  gardener  would  at  last  obtain 
quite  double  blossoms.  The  orange  day-lily,  too,  may 
sometimes  be  seen  with  one  or  more  stamens  enlarged 
into  small  petals  and  bearing  an  imperfect  anther. 

But  we  have  now  to  see  what  it  is  which  changes 
the  little  immature  grains  in  the  hollow  part  of  the 
pistil  into  seeds,  capable  of  growing  into  independent 
plants.  At  first  they  are  mere  specks  of  matter  to  all 
appearance,  and  so  they  will  remain  unless  they  are 
brought  into  close  contact  with  some  of  the  dust  con- 
tained in  the  sacs  borne  by  the  stamens.  This  is  the 
special  stimulant  which  they  need  to  make  them 


198  Blossom  and  Seed 

develop,  and  if  it  be  kept  from  them  they  will  simply 
shrivel  and  die,  for  nothing  else  will  do  instead. 

This  dust,  or  pollen,  is  contained  in  the  anther, 
which  is  usually  seated,  or  more  often  perched,  and 
apparently  very  loosely  perched,  too,  on  the  end  of  a 
stalk. 

When  the  pollen  is  ripe,  that  is,  ready  for  the  use  of 
the  grains  contained  in  the  pistil,  the  chambers  open 
and  it  is  discharged.  The  pollen  consists  of  hollow 
grains,  varying  very  much  in  size  and  shape  in  different 
plants,  though  always  alike  in  the  same  plant. 

Pollen-grains  are  very  beautiful  objects  when  seen 
through  the  microscope,  though  they  look  like  nothing 
but  powdery  dust  to  the  naked  eye.  Their  colour  is 
usually  yellow  or  brown,  but  they  are  also  red,  green, 
blue,  whitish,  and  even  black ;  and  though  their 
general  shape  is  round,  or  egg-shaped,  they  are  of  many 
other  forms,  wonderful  in  their  great  beauty  and 
variety,  and  reminding  one  of  microscopic  shells. 

Some  pollen-grains,  for  instance,  are  covered  with 
ridges  or  grooves ;  others,  such  as  those  of  the  holly- 
hock and  aster,  with  spines ;  others  again  with  hairs 
or  thorns ;  those  of  the  thistle  are  many-sided  ;  of 
the  fuchsia  and  evening  primrose,  triangular;  of  the 
chicory,  six-sided;  and,  if  we  could,  see,  we  should  no 
doubt  find  a  reason  for  every  change  of  form  and 
colour,  and  discover  that  each  was  exactly  adapted 
for  its  own  special  purpose. 

Every  pollen-grain  is  delicately  coated  with  oil,  pro- 
bably as  a  protection  against  damp  and  wet,  and  all 
have  upon  them  markings,  like  pores  or  slits,  to  some 
of  which  there  are  lid-like  covers.  Usually  each  grain 
consists  of  a  single  cell,  though  sometimes  there  are 


Blossom  and  Seed  199 

more,  and  the  cells  are  rilled  with  a  liquid  of  a  most 
nutritious  kind,  consisting  partly  of  starch,  partly  of  oil, 
and  partly  of  some  jelly-like  nitrogenous  compound. 

It  is  pollen  which  is  the  flesh-forming  food  of  the 
bee.  It  may  live  on  honey,  which  is  mainly  sugar — 
not  nitrogenous — during  the  winter,  when  it  is  doing 
no  work,  but  when  it  is  taking  long  journeys  to  and 
fro,  it  needs  something  more  nutritious  to  make  up  for 
the  waste  occasioned  by  so  much  muscular  exercise, 
and  it  eats  pollen,  besides  carrying  it  home  to  make 
bee-bread  for  the  young  grubs. 

But  our  concern  now  is  with  the  ovules,  the  possible 


Po».en  of  Wheat.  Pollen  of  the  Hollyhock. 

seeds,  lying  enclosed  in  the  ovary  at  the  base  of  the 
pistil,  while  the  pollen,  which  is  to  make  seeds  of  them, 
is  in  the  anther-sacs  above,  and,  as  it  would  seem,  out 
of,  and  beyond  their  reach.  The  question  is,  how  are 
the  two  to  be  brought  together  ? 

In  describing  the  primrose,  we  mentioned  that  the 
top  of  the  pistil  ends  in  a  knob ;  and  this  knob  is  a 
matter  of  great  importance.  It  is  called  the  stigma, 
and  is  of  all  sorts  of  different  shapes  in  different 
flowers ;  sometimes  merely  a  point,  sometimes  large 
and  divided  into  lobes,  sometimes  feathery,  as  in  most 
of  the  grasses ;  but  whatever  its  shape,  it  has  no 
covering  of  outer  skin,  as  the  stalk  on  which  it  is 
borne  has,  and  it  is  more  or  less  sticky,  and  often 
crowned  with  a  bead  of  nectar.  This  bead  is  so  large 


2  CO 


Blossom  and  Seed 


in  some  plants — as,  for  instance,  the  white  lily — that  it 
may  be  taken  off ;  and  if  then  a  few  grains  of  pollen 
from  the  anther  be  sprinkled  upon  it,  we  shall  see  that 
these  will  in  about  half  an  hour  begin  to  swell  and 
grow.  Each  grain  will  put  forth  a  slender  tube,  very 
minute,  of  course ;  but  in  an  hour  or  two  it  will  have 
lengthened  out,  and  the  fluid  contained  in  the  pollen- 


Throwing  out  the  Pollen  Tube. 

grain  may  be  seen  passing  down  one  side  of  the  tube 
and  up  the  other.  Pollen-grains  may  also  be  grown  in 
a  solution  of  gum  or  sugar. 

Now  this  is  exactly  what  takes  place  when  pollen 
falls  upon  the  sticky  stigma  at  the  tip  of  the  pistil,  only 
that  instead  of  growing  in  an  objectless  way,  each  grain 


Blossom  and  Seed  201 

sends  out  its  tube,  or  sometimes  several  tubes,  in  the 
most  business-like  manner,  and  with  the  most  precise 
and  definite  aim.  The  object  is  to  reach  one  of  the 
ovules  below,  and  to  do  this  the  tube,  in  many  cases  of 
more  than  hair-like  fineness,  pierces  its  way  downwards 
through  the  stalk  of  the  pistil,  and  makes  straight  for 
its  aim  with  unerring  exactness,  entering  one  of  the 
ovules  by  an  opening  in  it  which  exists  for  this 
purpose. 

Sometimes  the  tube  may  take  months  to  reach  the 
ovule,  but  more  usually  it  accomplishes  its  purpose  in  a 
few  days  or  hours.  As  soon  as  it  has  made  its  way  into 
the  ovule,  it  begins  to  pass  into  it  the  fluid  contents  of 
the  pollen-grain,  and  the  ovule  begins  to  grow. 

But  the  ovule  does  more  than  grow,  it  acquires  a  new 
character.  At  first  it  was  a  mere  speck  of  matter,  con- 
taining a  germ-cell,  indeed,  but  no  germ,  no  rudi- 
mentary or  embryo  plantlet,  such  as  one  may  see  on 
splitting  open  a  bean,  pea,  nut,  or  any  other  seed  large 
enough  for  the  purpose.  The  tube  sent  out  by  the 
pollen-grain  enters  the  ovule,  and  the  germ  is  developed 
and  vivified  by  the  liquid  which  passes  down  it.  The 
seed,  which  before  was  unfertile,  and  could  never  have 
germinated  and  produced  a  plant,  is  now  fertilized, 
made  fruitful,  and  if  allowed  to  come  to  maturity  it  will 
be  capable  of  producing  a  plant  like  that  by  which  it  is 
borne. 

It  is  quite  possible  in  certain  cases  for  ovules  to  grow 
and  even  to  attain  the  size  of  seeds  without  being  seeds, 
without  having  within  them  any  living  germ  .capable  of 
independent  life  and  growth.  For  each  ovule  is  at- 
tached to  the  walls  of  its  nursery,  as  one  may  see  by 
looking  at  the  peas  in  a  pod,  and  is  fed  from  the  leaves. 


2O2  Blossom  and  Seed 

But  unless  it  receives  also  the  liquid  contained  in  the 
pollen-grain,  it  remains  lifeless,  and  sooner  or  later 
shrivels  and  perishes. 

The  quantity  of  pollen  prepared  and  needed  for  the 
ovules  varies  very  greatly  in  different  plants.  The 
violet,  for  instance,  produces  about  a  hundred  grains  in 
each  blossom,  and  the  poppy  more  than  three  million 
and  a  half.  Some  ovules  need  only  two  or  three  grains 
of  pollen  to  quicken  them,  and  others  several ;  some  of 
the  foreign  orchids  bear  as  many  as  seventy-four 
million  seeds,  and  though  they  are  very  small,  each 
seed  requires  the  contents  of  about  twenty  grains  of 
pollen  to  fertilise  it ;  so  that  the  quantity  produced  is 
necessarily  very  large.  Moreover,  a  good  deal  more  is 
required  than  the  plant  itself  needs,  as  a  considerable 
margin  must  be  allowed  for  waste,  some  being  blown 
away  by  the  wind,  some  washed  away  by  rain,  and  not 
a  little  consumed  by  bees  and  other  insects. 

Since  the  pistil  with  its  sticky  tip  stands  in  the 
middle  of  the  blossom  all  ready  to  catch  and  hold  fast 
the  pollen  which  is  discharged  by  the  surrounding  dust- 
spikes,  it  would  seem  that  there  could  be  little  difficulty 
about  the  matter,  and  that  stamens  and  pistils  might 
safely  be  left  to  manage  it  without  help.  But  there  are 
various  obstacles  in  the  way  of  this  apparently  simple 
arrangement. 

In  the  first  place,  even  though  stamens  and  pistil  be 
most  conveniently  placed,  as  it  might  seem,  for  the  very 
purpose  of  giving  and  receiving  pollen,  it  does  not 
follow  that  they  are  so.  For  where  is  the  use  of  their 
being  within  easy  reach  of  one  another  if  they  are  not 
both  ready  to  act  at  the  same  time?  And  this  is  a 
thing  which  happens  very  frequently  indeed.  Some- 


Blossom  and  Seed  203 

times  the  pistil  is  ready  first ;  its  tip  is  unfolded  and 
sticky,  and  waiting  for  pollen,  before  that  of  the  sur- 
rounding stamens  is  ripe  enough  to  burst  from  the 
anthers.  But  the  pistil  cannot  go  on  waiting,  and  if 
pollen  does  not  reach  it  at  the  right  time,  it  is  of  no  use 
its  coming  at  all ;  the  time  is  gone  by,  and  the  ovules 
are  left  to  shrivel. 

Often,  too,  the  pollen  is  ripe  first  and  all  scattered 
before  the  pistil  is  ready  for  it ;  and  here  again  the 
ovules  must  perish,  unless  pollen  is  brought  from  else- 
where. Even  when  pollen  and  pistil  are  ripe  together, 
they  may  be  out  of  one  another's  reach  ;  for  the  pistil 
may  be  taller  than  the  stamens,  or  the  anthers  may 
open  outwards  instead  of  inwards,  and  in  neither  case 
will  the  pollen  be  scattered  on  the  pistil-tip,  or  be  of 
any  use  to  the  ovules. 

But  there  are  more  difficulties  even  than  these.  A 
perfect  flower,  as  has  been  said,  consists  of  a  double 
set  of  outer  and  a  double  set  of  inner  organs  ;  but  very 
many  flowers  are  quite  imperfect.  One  or  both  of  the 
outer  set  of  leaves  may  be  altogether  wanting,  and  one 
or  other  of  the  inner  set  may  be  also  wanting.  That  is 
to  say,  some  plants  grow  the  pistil  in  one  blossom  and 
the  stamens  in  another,  but  never  both  in  the  same 
blossom  ;  and  others  go  a  step  further  than  this,  and 
grow  their  pistils  and  stamens  not  merely  in  different 
blossoms,  but  on  different  plants. 

Those  plants  or  blossoms,  which  bear  stamens  only, 
are  of  course  barren,  for  they  posssss  no  ovules,  as  they 
possess  no  pistils ;  and  those  which  bear  pistils  only 
are,  or  may  be,  fertile,  since  they  possess  ovules,  which 
may  become  seeds  provided  pollen  be  brought  to  them 
from  another  blossom  or  plant,  but  not  otherwise. 


204  Blossom  and  Seed 

And  then,  again,  even  when  a  plant  bears  perfect 
flowers  with  both  pistils  and  stamens,  it  not  unfre- 
quently  happens  that  pollen  from  their  own  blossom, 
or  from  another  blossom  on  the  same  stalk,  does  not 
suit  the  ovules.  Some  which  are  fertilized  by  the  pollen 
of  their  own  blossom,  close-fertilized,  as  it  is  called,  do 
well,  and  the  seed  is  plentiful ;  but  in  most  cases  it  is 
poor  and  even  worthless.  Sometimes  the  pollen  from 
a  blossom  on  the  same  stalk  actually  has  the  effect  of 
poison,  and  when  applied  to  the  pistil-tip,  causes  it  to 
shrivel  and  decay,  and  makes  the  petals  drop  ;  some- 
times, again,  it  does  neither  good  nor  harm  directly  ; 
it  does  not  poison  and  it  does  not  fertilize,  but — which 
is  equally  injurious — it  prevents  any  other  pollen  re- 
ceived afterwards  from  having  any  effect,  so  that  in 
either  case  the  ovules  are  equally  sure  to  shrivel. 
Then,  further,  there  are  some  plants,  as,  for  instance, 
certain  of  the  passion-flowers,  whose  ovules  cannot  be 
converted  into  seeds  unless  they  receive  pollen  not 
merely  from  another  plant  of  the  same  species,  but 
from  another  plant  of  a  different  species— a  passion- 
flower, but  a  different  species  of  passion-flower. 

Such,  then,  being  some  of  the  many  arrangements  by 
which  it  is  made  difficult  or  impossible,  for  ovules  to  be 
fertilized  by  pollen  from  their  own  blossom,  or  from  a 
blossom  on  the  same  stalk,  one  must  conclude  that 
there  is  some  reason  for  them,  and  that  seed  is  the 
better  for  being  cross-fertilized — fertilized,  that  is,  by 
pollen  from  another  plant.  And  so,  indeed,  it  proves  ; 
for  if  cross-fertilized  and  self-fertilized  seeds  be  sown 
together,  it  generally  happens  that  the  former  grow  up 
so  much  the  stronger  as  quite  to  overpower  the  rest. 

As  a  rule,  then,  cross-fertilized  seed  produces  much 


Blossom  and  Seed  205 

more  vigorous  plants  than  self-fertilized  seed  does.  But 
still,  as  wild  plants  have  to  keep  their  own  place  in  the 
world,  which  they  cannot  do  without  offspring,  it  is 
better  for  them  to  have  some  seed,  even  poor  seed, 
rather  than  none  at  all.  And  to  ensure  this  some 
plants  manage  to  bear  seed  of  both  sorts ;  some  fer- 
tilized by  the  pollen  of  its  own  blossom,  some  if  possible 
by  that  brought  from  outside,  so  that  if  by  any  chance 
the  latter  should  fail,  they  may  still  have  something  to 
fall  back  upon. 

There  is,  for  instance,  that  ubiquitous  little  plant, 
the  common  chickweed — weak-stemmed  and  fragile- 
looking,  but  not  in  the  smallest  danger  of  dying  out, 
for  it  goes  on  sowing  itself  through  many  months  of 
the  year.  Its  first  crop  of  seed  is  fertilized  quite  early 
in  the  spring,  so  early  that  the  plant  is  left  to  itself, 
and  has  to  make  the  best  of  its  own  pollen,  which  it 
does  in  the  most  thrifty  way  possible.  The  pollen  is 
never  scattered,  so  there  is  no  waste,  but,  while  still  in 
the  anther-sacs,  it  sends  out  tubes  in  the  direction  of 
the  pistil-tip,  which  it  reaches  without  fail.  This  pro- 
cess takes  place  while  the  flowers  are  still  only  buds,  so 
that  pollen  and  tubes  are  carefully  protected.  The 
seed  thus  produced  may  be  poor,  much  of  it  may  even 
be  useless,  but  at  least  what  there  is,  is  better  than 
none ;  and  later  in  the  season,  if  circumstances  are 
favourable,  better  seed  will  be  produced  by  pollen 
brought  from  other  plants. 

Generally  speaking,  pollen  grains  do  not  begin  to 
swell  until  they  actually  touch  the  moist  tip  of  the 
pistil,  but  in  these  early  blossoms  of  the  chickweed 
and  some  other  plants,  they  never  leave  the  anthers. 
The  sweet  violet,  in  like  manner,  bears  some  buds, 


2o6  Blossom  and  Seed 

smaller  than  the  rest,  which  never  open.  These  pro- 
duce but  a  few  grains  of  pollen,  as  there  is  no  waste 
to  be  allowed  for,  and  they  send  out  long  tubes  without 
leaving  the  anthers. 

The  dog-violet,  on  the  other  hand,  as  it  does  not 
resort  to  this  device,  is  quite  seedless,  unless  pollen  be 
brought  to  it ;  and  other  plants  are  much  worse  off, 
and  can  never  set  seed  at  all  in  this  country,  being 
unable  to  make  use  of  their  own  pollen,  and  not  find- 
ing here  the  messengers  which,  in  their  native  land, 
bring  them  pollen  from  other  plants.  The  Greater 
Periwinkle  is  one  of  these,  and  never  has  seed. 

As  has  been  mentioned,  some  blossoms  have  pistils 
so  much  longer  than  the  stamens  that  it  seems  impos- 
sible for  the  pollen  of  the  one  to  reach  the  tip  of  the 
former.  This  is  the  case  with  the  colchicum,  whose 
mauve-coloured  blossoms  are  much  like  those  of 
the  crocus.  But  when  the  pollen  is  ripe  and  the 
anthers  have  burst,  some  of  the  dust  is  rubbed  off 
upon  the  inside  of  the  petals  when  the  flower  closes, 
as  it  does  every  night  several  times  in  succession. 
Meanwhile  the  petals  lengthen  so  much  that,  when  the 
blossom  closes  for  the  last  time,  the  first  spots  of 
pollen  are  brought  up  to  a  level  with  the  tip  of  the 
pistil  and  are  pressed  against  it,  with  the  result  that 
some  of  the  grains  adhere  to  the  sticky  surface  and 
soon  begin  to  grow,  at  the  rate  of  something  more 
than  an  inch  in  an  hour. 

In  the  case  of  the  colchicum,  the  ovules  are  a  very 
long  way  from  the  pistil-tip — as  much  as  thirteen 
inches — but  they  are  reached  in  about  twelve  hours. 
This  takes  place  at  latest  at  the  beginning  of 
November ;  but,  for  some  reason,  perhaps  because  it 


Blossom  and  Seed  207 

needs  warmth,  the  germ  or  embryo  does  not  begin  to 
form  in  the  ovules  until  the  following  May. 

The  ovules  of  the  American  oak  wait  almost  a  year 
after  the  entrance  of  the  pollen-tube  before  they  begin 
to  develop,  and  then  take  another  year  to  ripen. 

Why  should  the  pollen-tube  always  grow  with  its 
end  directly  towards  the  very  narrow  opening  by  which 
it  is  to  enter  the  ovule  ? 

For  the  ovule  is  often  far  away — what,  considering 
the  size  of  the  pollen-grain,  may  be  called,  without 
exaggeration,  hundreds  of  miles  away — while  the  door 
by  which  alone  the  tube  can  find  entrance  is  the 
merest  point.  Indeed,  the  ovules  themselves  are  often 
mere  specks,  and  usually  they  are  placed  in  what  looks 
like  a  most  inaccessible  position,  quite  enclosed  in  the 
ovary.  Often,  too,  there  are  hundreds,  and  even 
thousands,  of  ovules  in  one  ovary,  each  of  which 
receives  at  least  one  pollen-tube,  in  some  cases  more. 

Even  when  it  has  taken  the  first  turn  downwards 
in  the  right  direction  there  is  plenty  of  room — either 
on  its  way  down  the  pistil  stalk  or  when  it  reaches  the 
ovary — for  the  tube  to  go  astray.  But  instead  of  doing 
so  it  makes  unerringly  for  its  mark,  and  we  can  only 
conclude  that  some  definite  arrangements  exist  by  which 
it  is  directed  into,  and  kept  in,  the  right  way. 


XV. 

THE   GOLDEN   RULE   FOR  FLOWERS 

* "  GET  fertilized  !  cross-fertilized,  if  you  can,  self- 
fertilized  if  you  must/'  that  is  nature's  golden  rule  for 
flowers.' 

We  have  mentioned  only  a  few  of  the  curious  and 
interesting  arrangements  by  which  the  pollen  is  in 
very  many  cases  prevented  from  coming  in  contact 
with  the  ovules  of  its  own  blossom ;  but  enough  has 
been  said  to  show  that  this  <  elf-fertilization  is  generally 
discouraged,  and  made  in  many  cases  either  difficult 
or  altogether  impossible. 

We  have  now  to  see  how  cross-fertilization  is 
provided  for,  and  by  what  messengers  pollen  is  con- 
veyed from  one  blossom  to  another.  These  messengers 
are  wind,  insects  of  many  kinds,  birds,  and  even  in 
some  instances  that  most  unlikely  of  gardeners,  the  ill- 
reputed  snail. 

Plants  which  depend  upon  the  wind  for  bringing 
them  the  needful  pollen  have  small,  inconspicuous, 
and  generally  scentless  blossoms  ;  bright  colours,  sweet 
scents,  and  honey,  being  usually  confined  to  those 
plants  which  need  the  services  of  birds  and  insects.  The 
pistil-tips  or  stigmas  of  the  former  are  also  especially 


The  Golden  Rule  for  Flowers  209 

adapted  for  catching  and  holding  the  grains  of  pollen 
blown  upon  them,  for  they  are  either  divided  into 
plumes  or  feathers,  or  are  plentifully  beset  with  hairs. 
Grasses  and  sedges  are  chiefly  wind-fertilized  ;  and  so, 
too,  are  many  trees,  such  as  the  oak,  beech,  hazel, 
birch,  elm,  poplar  and  pine,  all  of  which  blossom  early 
in  the  year,  often  before  there  are  any  leaves  to  inter- 
fere with  the  scattering  of  the  pollen ;  and  they  mostly 
bear  pollen  and  ovules  in  separate  blossoms,  some  on 
the  same  tree,  some  on  different  trees. 

The  pollen-bearing,  or  staminate  blossoms  of  these 
trees  grow  together  in  large  numbers,  in  the  form  of 
tassels  or  catkins,  which  wither  and  drop  when  their 
pollen  is  scattered  and  their  work  done. 

The  catkins  of  the  hazel  contain  more  than  a 
hundred  blossoms,  having  no  petals,  but  ten  or  twelve 
stamens  each.  The  blossoms  containing  the  ovules 
grow  on  the  same  tree,  but  they  have  no  petals  either, 
and  are  so  small  as  almost  to  escape  notice,  for  they 
look  like  nothing  but  small  scaly  buds,  with  tiny  crim- 
son tufts  on  the  top.  These  crimson  tufts  are  the 
stigmas,  outspread  on  purpose  to  catch  the  grains  of 
pollen  as  they  float  by. 

Pines,  on  the  other  hand,  have  not  only  no  petals, 
but  no  pistil-stalks,  and  not  even  stigmas  either;  all 
that  there  is  of  the  pistil  being  the  ovary,  which  is 
scale-shaped  and  open,  so  that  the  pollen  falls  directly 
upon  the  ovules  within  it.  As  the  ovules  develop  into 
seeds  and  grow,  the  scales  that  bear  them  grow  also, 
and  ripen  into  fir-cones. 

Pollen  which  has  to  be  carried  by  the  wind  is  light, 
dry  and  powdery,  and  is  produced  in  very  large  quanti- 

14 


2io  The  Golden  Rule  for  Flowers 

ties  to  allow  for  the  unavoidable  waste.  It  is  carried 
far  and  wide,  and  the  air  is  often  rilled  with  it,  espe- 
cially in  the  neighbourhood  of  forests.  Masses  of  pine- 
pollen  are  often  found  in  America  as  much  as  three  or 
four  hundred  miles  away  from  any  trees  which  could 
have  produced  it.  Of  course,  where  plants  are  depen- 
dent upon  the  wind  for  pollen,  they  are  liable  to  have  a 
great  variety  of  it  brought  to  them ;  but  this  does  not 
hurt  them,  for  unless  the  right  kind  comes  it  simply 
has  no  effect  whatever.  But  as  it  is  of  great  import- 
ance to  these  plants  not  to  miss  any  chance  of  the 
right  pollen,  and  as  the  wind  blows  at  all  times,  night 
and  day,  they  never  close,  many  being  unable  to  do  so 
from  want  of  petals,  so  that  they  are  always  ready  to 
receive  it. 

Among  the  trees  which  are  fertilized  at  least  in  part 
by  the  wind  are  the  palms,  whose  blossoms  are  small 
and  dull-looking,  and  enclosed — thousands  of  them 
together  —  in  a  sheath,  something  like  that  of  the 
arum.  But  some  of  the  palms  are  very  strongly 
scented,  and  when  the  sheath  opens  it  is  a  centre  of 
attraction  to  a  buzzing  cloud  of  flies,  small  beetles  and 
other  insects. 

The  date-palm  bears  ovules  and  pollen  on  separate 
trees ;  and  when  date  stones  are  planted  it  is  found 
that  instead  of  coming  up  half  of  one  sort  and  half  of 
the  other,  there  are  more  of  the  fruit-bearing  than  of 
the  unfruitful  trees  among  them. 

However,  one  pollen-bearing  tree  is  well  able  to 
supply  more  than  one  ovule-bearing  tree,  and  in  their 
wild  state  the  trees  have  no  difficulty  in  obtaining  all 
that  they  want.  But  when  they  are  cultivated  then 


The  Golden  Rule  for  Flowers          211 

they  require  help,  though  trees  of  both  kinds  grow  in 
the  same  plantation.  The  fact  is  mentioned  by  many 
writers,  from  Pliny  downwards,  though  without  expla- 
nation ;  and  in  all  the  plantations  part  of  the  work  con- 
sists in  climbing  the  trees,  first  to  collect  pollen-bearing 
blossoms,  and  next  to  dust  with  them  the  little  ovules, 
which  are  about  as  large  as  peas,  and  lie  exposed  in  the 
centre  of  the  other  blossoms,  not  enclosed  in  an  ovary. 
If  this  is  not  done  the  date  crop  fails. 

During  Napoleon's  campaigns  in  Egypt,  the  natives 
not  having  much  leisure  to  attend  to  husbandry,  the 
plantations  about  Cairo  were  neglected,  and  although 
the  trees  blossomed  as  usual  the  eatable  dates  were  few. 

In  the  East  dates  are  such  an  important  article  of 
food,  and  the  failure  of  the  crop  such  a  serious  loss, 
that  nations  at  war,  and  desirous  of  inflicting  as  much 
injury  as  possible  upon  one  another,  were  in  the  habit 
of  cutting  down,  not  all  the  palms  indiscriminately,  bui 
those  bearing  pollen.  On  one  occasion  it  is  said  that 
the  Persians,  fearing  they  might  be  injured  in  this  way 
during  a  civil  war,  took  the  precaution  of  collecting  the 
pollen  from  the  trees,  kept  it  in  close  vessels  for  nine- 
teen years,  and  made  successful  use  of  it  when  peace 
was  restored. 

The  Arabs  are  said  always  to  keep  some  of  the 
unopened  sheaths  containing  pollen  from  year  to  year, 
in  case  of  any  failure  in  the  blossoms. 

It  has  been  mentioned  that  pollen  may  often  be 
borne  long  distances  by  the  wind,  and  this  has  been 
exemplified  in  a  remarkably  interesting  way  by  the  case 
of  a  date-palm  growing  near  Otranto.  The  palm  is  not 
a  native  of  Italy,  and  though  introduced,  does  not  grow 


212  The  Golden  Rule  for  Flowers 

wild  ;  and  this  specimen,  being  the  only  one  of  its  kind 
in  the  neighbourhood,  was  barren  for  years.  But  at 
last,  one  year,  the  young  dates,  instead  of  shrivelling 
as  usual,  remained  on  the  tree  and  grew  to  their 
proper  size  ;  and  then  it  was  found  that  a  date  tree 
had  flowered  that  same  year  for  the  first  time  at  Brin- 
disi,  some  forty  odd  miles  away,  and  had  borne  pollen- 
blossoms.  This  pollen,  therefore,  had  no  doubt  been 
carried  by  the  wind  to  the  tree  at  Otranto. 

The  case  of  another  solitary  date  tree,  growing  at 
Martinique,  in  the  West  Indies,  is  also  interesting, 
though  in  another  way.  For  this  tree  bore  eatable 
fruit  without  being  fertilized,  but  though  the  dates 
might  be  eaten  the  stones  would  not  grow,  for  the 
seeds  were  imperfect,  and  contained  no  germ. 

The  fruit  of  a  plant,  botanically  speaking,  is  the 
ripened  pistil,  or  rather  that  part  of  the  pistil  which 
contains  the  ovules.  Sometimes,  as  in  the  case  of  the 
various  kinds  of  corn,  it  is  the  ripened  ovules,  the 
seeds,  which  are  the  eatable  part  of  the  fruit,  the  ovary 
in  which  they  are  contained  being  a  mere  husk.  In 
the  various  gourds,  on  the  other  hand,  the  ovary  itself 
grows  enormously  and  becomes  fleshy.  So,  too,  with 
apples,  pears,  peaches,  nectarines,  plums  and  oranges, 
the  swollen,  ripened  ovary  containing  the  seed  is  the 
part  best  worth  eating  ;  and  it  has,  therefore,  been  the 
gardeners'  object  to  increase  its  size  and  improve  its 
flavour.  In  the  almond,  the  ovary  remains  a  mere 
woolly  skin  without  edible  flesh  ;  in  the  horse-chestnut 
it  is  a  tough,  thick  and  prickly  skin,  equally  uneatable ; 
in  the  filbert  and  beech-nut  it  is  a  hard  shell ;  and  in 
the  coco  -  nut  it  consists  of  fibre.  Whether  husk, 


The  Golden  Ride  for  Flowers          213 

shell,  skin,  flesh  or  fibre,  however,  the  whole  ovary 
with  the  ripened  ovules  is  properly  the  plant's 
fruit. 

Generally  speaking,  the  growth  of  the  ovary,  as  well 
as  of  the  ovules,  depends  upon  pollen,  and  when  the 
ovules  are  fertilized  and  begin  to  grow,  the  ovary 
begins  to  develop  also,  and  not  until  then. 

But  it  is  not  always  so.  Among  the  plants  belonging 
to  the  order  of  Liliacese,  which  includes,  besides  lilies, 
the  hyacinth,  tulip,  garlic,  onion,  and  others,  it  is  a 
common  thing  for  the  ovary  to  begin  growing  actively 
before  the  pollen-tubes  have  reached  the  ovules — before 
they  are  fertilized,  therefore — though  not  before  the 
tubes  have  begun  to  penetrate  downwards  through  the 
style.  In  these  cases  the  ovary  seems  to  be  excited  to 
growth  by  the  pollen,  though  not  in  the  usual  way,  and 
before  the  ovules  are  affected. 

But  in  many  plants  the  ovary,  and  even  ovules,  may 
be  fully  developed,  altogether  without  pollen ;  though 
in  this  case  the  ovules  do  not  become  seeds  any  more 
than  the  f  stones '  of  the  Martinique  date  become  seeds, 
and  no  plant  can  be  raised  from  them. 

Among  the  plants  which  ripen  the  ovary  without  the 
help  of  pollen  are  the  Zante  '  currant '  (really  a  small 
grape),  many  Maltese  oranges,  and  some  kinds  of  apple. 

While  some  ovules  are  so  independent  as  to  be  able 
to  grow  to  the  size  of  seeds,  and  even  to  assume  the 
appearance  of  seeds,  without  being  fertilized,  there  are, 
on  the  other  hand,  some — as,  for  instance,  those  of  the 
orchids — which  are  not  even  formed  until  the  pollen- 
tubes  begin  to  grow  towards  the  place  where  they 
should  be.  The  pollen  in  these  cases  not  only  fertilizes 


214  The  Golden  R^lle  for  Flowers 

them,  but,  though  still  at  a  distance,  is  the  means  of 
bringing  them  into  being. 

Of  course,  as  pollen  is  so  light,  and  easily  blown 
about,  many  plants  may  at  times  be  fertilized  by  the 
wind,  besides  those  which  are  especially  dependent 
upon  it.  Not  many,  one  would  suppose,  are  fertilized 
by  water ;  yet  there  are  one  or  two  instances  of  this 
too  curious  to  be  passed  over. 

One  of  these  is  that  of  a  small  water-plant,  nearly 
related  to  the  duckweeds,  which  bears  two  blossoms 
enclosed  together  in  a  boat-shaped  sheath,  which  floats 
upon  the  water.  In  the  upper  part  of  the  sheath  is  a 
perfect  pistil,  with  its  ovary,  short  stalk,  and  stigma  ; 
in  the  lower  part  are  the  anthers  containing  pollen, 
which  cannot  by  any  possibility  reach  the  stigma  unless 
rain  happens  to  fall  when  it  is  ready.  If  it  does,  the 
sheath  is  gradually  filled  with  water,  and  the  pollen  is 
floated  up  till  it  reaches  the  right  place. 

There  is  a  still  more  curious  arrangement  in  the  case 
of  the  Vallisneria,  which  grows  in  the  ditches  in  Italy, 
and  is  well  known,  though  hot  in  a  flowering  state,  in 
fresh-water  aquariums.  This  plant  bears  its  pistillate 
and  staminate  blossoms  on  separate  roots,  which,  how- 
ever, seem  to  grow  near  one  another.  The  pistillate, 
fruit-bearing  blossom  grows  on  a  long,  slender  stalk 
twisted  like  a  corkscrew,  which  uncurls  and  raises  the 
bud  just  above  the  surface  of  the  water  when  it  is 
about  to  open.  The  barren,  staminate,  or  pollen- 
bearing  flowers,  grow  in  great  numbers  on  short,  up- 
right stalks  underwater  ;  but  just  about  the  time  when 
the  other  blossoms  up  above  open  and  want  their  help, 
these  buds  loose  themselves  from  their  stalks  and  rise 


The  Golden  Rule  for  Flowers          2 1 5 

up  like  little  air-bubbles,  opening  suddenly  when  they 
reach  the  surface.  Here  they  float  about  on  the  water 
among  the  pistillate  blossoms  in  such  numbers  that 
they  often  quite  cover  them,  and  by  this  means  convey 
to  them  the  necessary  pollen.  When  this  has  been 
received,  the  corkscrew  stalks,  which  are  often  as  much 
as  ten  feet  long,  curl  up  as  before,  and  the  fertilized 
blossoms  sink  down  again  to  ripen  their  fruit  under 
water. 

We  must  now,  however,  turn  to  the  insects,  among 
which  bees  have  a  foremost  claim  upon  our  attention, 
since  none  are  more  generally  useful  in  carrying  on  the 
very  important  work  of  fertilization.  Creeping  insects 
are  not,  as  a  rule,  useful  visitors  for  flowers,  as  any 
grains  of  pollen  which  they  may  pick  up  by  the  way 
are  liable  to  be  brushed  off  again  before  they  reach  a 
blossom  which  might  be  benefited.  But  flying  insects 
of  all  kinds,  even  to  the  smallest  flies  and  midges, 
when  once  dusted  with  pollen,  are  almost  sure  to 
convey  a  few  grains  to  the  next  blossom  upon  which 
they  alight. 

Pollen  is  of  vital  importance  to  the  plants  themselves, 
besides  serving  as  food  to  bees  and  other  insects ;  but 
nectar,  so  far  as  appears,  is  of  no  use  to  the  plant 
except  as  serving  to  attract  useful  visitors ;  and  the 
same  may  be  said  of  sweet  scents  and  brightly-coloured 
petals.  All  these  are,  in  fact,  the  one,  baits,  the  other, 
signals,  which  the  plant  puts  forth  to  make  known  to 
those  who  understand  the  language  where  pollen  and 
nectar  may  be  found. 

'  Good  entertainment  for  bees  and  butterflies '  is 
what  the  bright  colours  mean  ;  and  where,  as  is  often 


2 1 6  The  Golden  Rule  for  Flowers 

the  case,  the  nectar  is  concealed  in  some  deep  and  safe 
recess  where  wet  cannot  injure  it,  many  flowers  have 
lines  or  dots  upon  some  of  their  petals  to  point  out 
where  it  may  be  found,  and  so  save  their  visitors' 
time. 

Many  bees  have  a  regular  pollen-brush  of  thick  hairs 
under  their  tails,  with  which  they  sweep  up  the  grains ; 
and  even  when  their  object  is  nectar,  not  pollen,  they 
are  almost  sure  to  carry  off  a  few  grains  by  brushing 
against  the  anthers  of  the  blossom  they  are  visiting. 
For  all  bees  are  more  or  less  covered  with  hairs,  some 
of  which,  being  webbed,  are  especially  adapted  for 
holding  the  pollen-grains  ;  while  the  grains  themselves 
cling  all  the  better  for  the  spines  and  hairs  with  which 
they  are  often  beset. 

Small  insects  are  useful  for  fertilizing  small  flowers, 
but  they  may  light  upon  a  large  flower,  creep  in,  and 
even  rob  it  of  nectar,  without  coming  into  contact  with 
the  pollen  at  all,  which  is  almost  impossible  in  the  case 
of  the  larger  species  of  bees,  with  their  hairy  bodies. 
The  bee,  too,  has  another  recommendation  :  it  has  to 
visit  many  flowers  before  its  crop  is  filled  with  nectar, 
and  both  hive-bees  and  humble-bees,  especially  the 
latter,  seem  generally,  though  not  invariably,  to  confine 
their  visits  to  one  kind  of  flower  on  each  journey — a 
very  important  matter,  as  pollen  of  different  sorts 
would  in  most  cases  be  useless. 

Of  course,  the  bee  may,  and  does,  convey  pollen 
from  blossom  to  blossom  of  the  same  plant,  which  may 
produce  self-fertilization  of  a  sort ;  but  when  it  has 
visited  all  the  blossoms  on  one  plant,  and  flies  off  to 
another,  the  first  blossoms  visited  there  n\ust  needs 


The  Golden  Rule  for  Flowers          217 

stand  a  good  chance  of  receiving  pollen  from  the  last 
of  the  former. 

That  the  work  thus  done  by  bees  is  in  many  cases 
absolutely  indispensable  there  is  ample  proof,  though 
we  may  not  always  recognise  It. 

The  bean-crop  failed  in  Nicaragua  just  for  lack  of 
the  right  sort  of  bee ;  and  often  when  the  young  goose- 
berries, or  what  should  be  gooseberries,  wither  and 
drop  in  early  spring,  instead  of  swelling  as  they  ought 
to  do,  it  is  not  so  much  because  they  have  been  nipped 
by  the  frost  as  that  the  frost  has  kept  the  bees  at  home. 
For  the  pollen  and  pistils  of  the  gooseberry-blossoms 
ripen  at  different  times,  so  that  the  one  must  be  brought 
to  the  other  if  the  ovules  are  to  be  fertilized ;  and  if 
this  is  not  done,  neither  they  nor  the  berry  containing 
them  can  grow  to  their  proper  size. 

One  year  there  was  a  remarkable  scarcity  of  holly- 
berries  in  different  parts  of  the  country,  which  some 
people  thought  was  accounted  for  by  the  cold  weather 
in  the  early  part  of  the  year.  But  the  holly  is  a  very 
hardy  shrub,  and  grows  in  Norway  as  far  north  as  62°, 
so  that,  it  was  not  likely  to  have  suffered  from  an 
English  spring.  On  the  other  hand,  bees  were  re- 
markably rare  that  season  ;  and,  as  the  holly  grows  its 
stamens  and  pistils  mostly  on  different  plants,  the 
dearth  of  berries  was  doubtless  owing  to  the  absence 
of  bees. 

For,  though  holly-blossoms  are  insignificant,  they 
are  fertilized  chiefly  by  bees,  and  not  by  wind,  pollen 
having  been  observed  by  Mr.  Darwin  on  many  pistil- 
tips,  which  must  have  been  brought  from  a  tree  sixty 
yards  away,  and  could  not  have  been  conveyed 


2 1 8          The  Golden  Rule  for  Flowers 

by  the  wind,  since  it  was  blowing  in  the  wrong 
direction. 

The  year  that  the  holly-berries  failed,  the  crop  of 
clover-seed  failed  also  in  some  parts,  and  no  doubt 
from  the  same  cause.  For  though  some  clovers 
manage  to  fertilize  themselves  more  or  less,  there  is  a 
very  marked  difference  in  the  quantity  of  seed  borne 
by  the  plants,  according  as  they  are  kept  covered,  and 
out  of  the  way  of  insects,  or  not. 

A  hundred  heads  of  common  red  clover  bear  about 
2,720  seeds  among  them ;  but  a  hundred  heads  covered 
with  a  net  on  one  occasion,  to  keep  off  the  bees,  had 
not  one  single  seed.  This  common  red  clover  has  a 
tube,  too  long  to  be  sucked  by  the  hive-bee  until  it  has 
been  mown,  when  the  second  .crop  of  blossoms  are 
said  to  be  rather  smaller,  and  its  first  crop  is  dependent 
on  the  humble-bee.  A  very  slight  difference  in  length 
makes  just  all  the  difference  as  to  the  species  of  bee 
which  is  able  to  extract  nectar  from  the  blossom.  The 
brilliant  crimson-clover  is  frequented  by  the  hive-bee, 
its  tube  being  shorter  than  that  of  the  common  red 
kind. 

Strawberry  plants  are  altogether  dependent  upon 
bees  for  the  perfecting  of  their  fruit,  even  where  pollen 
and  ovules  are  produced  in  the  same  blossoms.  In 
one  species  of  strawberry,  the  true  Hautbois,  they  are 
borne  by  different  plants ;  and  in  the  great  market- 
gardens  of  America,  where  this  is  grown,  it  is  usual  to 
plant  one  row  of  barren  plants  to  every  three  rows  of 
fertile  ones,  leaving  the  bees  to  do  the  rest. 

A  great  deal  has  to  be  done  to  ensure  the  thorough 
fertilization  of  the  strawberry-ovules,  for  there  are 


The  Golden  Rule  for  Flowers          219 

from  a  hundred  to  three  hundred  in  each  fertile 
blossom,  and  there  are  an  equal  number  of  pistils. 
The  pistils  are  set  upon  a  cone-shaped  receptacle  in 
the  centre  of  the  blossom ;  each  one  contains  in  its 
ovary  a  single  ovule,  and  the  ovary  and  ovule  ripening 
together,  develop  into  a  tiny  nut,  which  is  the  fruit 
properly  speaking. 

As  the  nuts  grow,  the  conical  receptacle  on  which 
they  are  set  grows  too,  and  becomes  soft,  fleshy  and 
sweet,  forming  what  we  erroneously  call  the  '  berry.' 

But  if  the  '  berry '  is  to  grow  properly,  every  one  of 
the  pistils  must  receive  a  few  grains  of  pollen,  and  if 
any  are  left  out,  the  ovules  belonging  to  them  do  not 
grow,  and  the  part  of  the  receptacle  which  surrounds 
them  does  not  grow  either,  but  remains  hard.  The 
hard  spots  sometimes  found  in  strawberries,  with  a 
number  of  little  '  seeds '  crowded  together,  are  due 
simply  to  the  fact  that  the  ovules  have  not  been 
fertilized,  and  have  withered  instead  of  growing. 

So,  too,  with  the  raspberry.  Each  one  of  the  sixty 
or  seventy  little  fruits  composing  the  '  berry '  depends 
upon  pollen  for  the  power  of  developing,  not  only  its 
seed,  but  also  the  sweet,  juicy  envelope  surrounding 
each  seed.  Towards  the  end  of  the  season  these  often 
fail  and  wither,  because  the  bees  are  either  dying  off, 
or  do  not  care  to  come  out  unless  the  weather  is 
tempting. 

Then  again  with  apples  :  one  may  often  see  an  apple 
which  is  deformed,  having  grown  on  one  side;  and 
the  reason  here,  too,  is  similar. 

The  calyx  of  the  apple-blossom  is  a  tube  which 
spreads  out  at  the  top  into  five  leaf-like  divisions. 


220  The  Golden  Rule  for  Flowers 

Inside  the  tube,  and  joined  to  it,  are  the  ovaries, 
which  together  form  the  horny  core.  When  the 
stigmas  are  all  properly  dusted  with  pollen,  each 
ovary,  with  its  two  pips,  begins  to  grow ;  but,  if 
nothing  else  grew,  there  would  be  no  apple,  only  a 
horny  seed-vessel,  the  only  eatable  part  of  which 
would  be  the  seeds.  But  the  calyx  enclosing  the  core 
grows  too,  and  so  does  the  top  of  the  stalk  from  which 
it  springs ;  and  it  is  these  which  together  form  the  apple. 

If,  however,  one  of  the  stigmas  be  by  chance  left 
without  pollen,  then  the  ovary  belonging  to  it,  with  its 
two  pips  and  the  part  of  the  calyx  next  to  it,  does  not 
grow,  and  the  apple  is  misshapen. 

There  is  a  French  apple  called  the  S.  Valery  apple, 
which  is  remarkable  for  having  a  double  calyx  and  a 
double  core,  with  ten  divisions,  but  no  petals,  and  only 
imperfect  stamens,  which  produce  no  pollen.  This 
has  to  come,  therefore,  from  different  varieties,  and  it 
is  a  regular  custom  for  the  girls  of  S.  Valery  to  go  to 
the  orchards  in  the  spring,  taking  pollen  from  various 
other  apple-trees,  to,  as  they  say,  *  make  their  apples.' 
Each  marks  with  ribbons  her  own  fruit,  and  the 
different  pollen  produces  apples  of  different  flavour, 
colour  and  size,  according  to  the  variety  of  apple  from 
which  the  pollen  has  been  taken. 

Occasionally  one  hears  of  an  apple-tree  which  in- 
dulges in  the  freak  of  bearing  fruit,  some  of  which  is 
of  the  ordinary  shape,  and  some  />0#r-shaped,  both 
sorts  growing  on  the  same  twigs.  In  this  case  one 
must  suppose  that  the  bees  have  been  less  particular 
than  usual,  and  have  dusted  the  pistil-tips  with  pear- 
pollen.  So,  too,  an  orange  blossom  crossed  with 


The  Golden  Rule  for  Flowers          221 

pollen  from  a  lemon  will  bear  fruit  which  is  partly 
orange,  partly  lemon,  with,  peel  partly  of  the  one,  partly 
of  the  other. 

Among  the  many  plants  visited  by  bees,  large  or 
small,  are  the  foxglove,  mallow,  and  campanula,  all  of 
which,  though  they  grow  pistils  and  stamens  together, 
ripen  them  at  different  times.  Anyone  not  knowing 
this,  and  examining  a  campanula  blossom,  would  be 
puzzled  to  know  what  could  have  become  of  the 
stamens,  for  when  the  flower  opens  they  have  generally 
vanished  ;  the  pollen  is  there  still,  however,  having 
been  discharged  upon  the  stalk  of  the  pistil  before  the 
bud  opened,  after  which  the  stamens  shrivelled  away. 
It  is  caught  and  held  by  the  hairs  with  which  the  stalk 
of  the  pistil  is  clothed,  apparently  for  the  very  pur- 
pose of  holding  it  until  the  bees  come  and  carry  it  off. 
When  the  pollen  is  gone,  the  tip  of  the  pfstil  unfolds 
from  three  to  five  spreading  branches  which  no  pollen 
can  reach  while  they  remain  folded  ;  and  then,  back 
come  the  bees,  this  time  in  search  of  nectar,  but 
bringing  with  them  grains  of  pollen  in  abundance  from 
other  flowers. 

Some  pistils,  as  has  been  said,  are  actually  poisoned* 
and  others  unaffected  by  the  pollen  of  their  own  sur- 
rounding stamens.  But  there  are  others  which  carry 
their  likes  and  dislikes  a  point  further  still,  and  require 
pollen,  not  merely  from  the  blossoms  of  another  plant, 
but  from  blossoms  whose  stamens  grow  at  exactly  the 
right  height ;  and  if  it  comes  from  stamens  too  short, 
or  too  long,  they  can  make  little  if  any  use  of  it. 

There  is,  for  instance,  the  Great  Purple  Loosestrife, 
whose  tall,  handsome  spikes  of  blossom  light  up  the 


222  The  Golden  Rule  for  Flowers 

river  banks.  The  pistils  and  stamens  of  this  plant  are 
of  three  different  sizes,  but  they  correspond  exactly  in 
height,  long  pistils  with  long  stamens,  short  with  short, 
and  middle-sized  with  middle-sized.  The  long  stamens 
have  emerald  green  pollen,  the  others  yellow ;  and  the 
grains  vary  in  size  with  the  length  of  the  stamens,  the 
longer  the  stamens  the  larger  the  grains ;  for  the 
larger  grains  are  destined  for  the  longer  pistils,  and 
have,  of  course,  to  send  out  longer  tubes  in  order  to 
reach  the  ovules. 

A  bee  entering  a  blossom  in  search  of  honey  is 
dusted  with  pollen  on  different  parts  of  its  body, 
according  to  the  height  of  the  "stamens,  and  when  it 
flies  off  to  the  blossoms  of  another  plant,  if  the  spots 
of  dust  come  in  contact  with  pistil-tips  of  the  proper 
height  they  may  be  caught  and  kept. 

The  red  Oxalis  is  another  of  the  plants  having 
pistils  and  stamens  of  three  sizes,  and  a  large  field  in 
Brazil  containing  many  acres  of  this  plant  yielded  not 
a  single  seed,  because,  though  pollen  and  insects  were 
both  plentiful,  all  the  plants  chanced  to  be  of  the  same 
'  form,'  as  it  is  called :  all  had  long  pistils  and  short 
stamens,  or  vice  versa,  and  the  pollen  was  of  no  use. 
Other  plants  possess  similar  peculiarities,  but  we  will 
mention  one  which  all  can  examine  for  themselves — 
the  common  yellow  primrose. 

The  blossom  of  the  primrose  is  a  long  tube  flattened 
out  at  the  top  into  five  divisions.  If  we  look  at  a 
bunch  of  primroses  gathered  from  different  plants,  we 
see  at  once  that  all  are  not  alike.  In  some  the  pistil, 
with  a  knob  like  a  pin's  head,  stands  up  just  out  of  the 
tube;  in  others  no  pistil  is  visible,  but  in  its  place, 


The  Golden  Rule  for  Flowers  223 

just  at  the  same  height,  are  five  stamens  standing  up 
like  teeth,  the  stalks  being  so  very  short  that  they  are 
almost  all  anther.  In  spite  of  their  shortness,  how- 
ever, the  stamens  are  on  a  level  with  the  long  pistil  of 
the  other  blossom,  for  they  are  attached  to  the  flower 
tube ;  and  for  the  long  pistil  their  pollen  is  intended. 
The  pollen  grains  of  the  stamens  which  grow  with  the 
long  pistil — but  out  of  sight,  half-way  down  the  tube — 
are  intended  for  the  short  pistil,  whose  knob  is  just  at 
their  own  level,  and,  accordingly,  they  are  smaller. 

All  flowers  which  vary  in  this  way,  all  which  are 
distinguished  by  colour,  scent,  size,  or  irregularity  of 
shape,  are  mainly  indebted  for  fertilization  to  insects. 
This  is  the  case  with  all  bell-shaped  and  tubular 
flowers,  also  with  the  snap-dragon  and  foxgloves,  and 
with  the  dead  nettles,  lavender,  thyme,  and  all 
blossom  of  similar  shape  to  these,  besides  many  others. 
In  some  the  shapes  of  the  blossom  and  of  the  insect 
by  which  it  is  fertilized  are  as  beautifully  and  'exactly 
fitted  one  to  the  other  as  the  lock  is  to  the  key,'  and  in 
others  there  are  endless  different  devices  for  securing 
that  the  visitor  shall  not  depart  without  doing  some 
service  in  return  for  the  pollen  or  nectar  which  it  has 
consumed  or  carried  off. 

In  the  common  stinging  nettle  the  four  stamens  lie 
folded  down  flat  until  they  are  touched,  when  they 
spring  suddenly  up  and  scatter  their  pollen  ;  a  needle 
inserted  in  the  throat  of  the  common  purple  lucerne 
causes  two  stamens  instantly  to  start  up  like  a  jack-in- 
the-box,  the  anthers  at  the  same  time  exploding  and 
discharging  their  dust.  A  similar  explosion  takes 
place  in  the  flowers  of  the  whin  and  ia  many  others. 


224  The  Golden  Rule  for  Flowers 

In  one  plant  the  anthers  act  like  a  pair  of  bellows,  and 
on  being  touched  blow  their  dust  out  upon  the  insect ; 
in  another — the  Kalmia,  or  American  mountain-laurel, 
the  stamens  rise  up  from  the  petals  on  which  they 
usually  lie  flat,  and  close  round  the  insect,  clasping  it 
and  impressing  their  pollen  upon  its  body. 

But  the  various  arrangements  are  so  numerous  that 
it  is  impossible  to  do  more  here  than  give  the  merest 
outline-sketch  of  them,  and  for  fuller  particulars  the 
reader  must  be  referred  elsewhere. 

We  have  confined  our  attention  hitherto  chiefly  to 
bees,  because  they  are  the  most  generally  useful  of 
insects,  and  few  flowers  seem  to  "come  amiss  to  them 
if  only  they  can  reach  the  nectar.  But  there  are  just  a 
few  flowers  which  they  actually  avoid.  Bees  of  all 
kinds,  for  instance,  shun  the  Crown-imperial,  though  it 
blossoms  in  March  and  April,  when  bee  food  is  not 
plentiful.  Gilbert  White  noticed  a  small  bird  like  a 
white-throat  running  up  the  stems  of  this  plant  and 
plunging  its  head  into  the  bells  in  search  of  nectar,  so 
it  may  be  that  it  is  fertilized  in  this  way,  for  it  certainly 
sets  seed. 

Other  flowers  disliked  by  bees  are  the  passion-flower 
and  dahlia — which  seem  to  stupefy  and  often  kill  them, 
and,  above  all,  the  oleander,  whose  nectar  is  fatal.  A 
traveller  in  Hungary  and  Dalmatia,  where  the  oleander 
abounds,  could  not  remember  ever  to  have  seen  bee, 
moth  or  butterfly  visiting  the  blossoms.  And  yet  their 
bright  rose-coloured  petals  seem  to  say,  in  the  language 
of  flowers,  that  they  need  the  help  of  insects,  and 
those,  too,  of  a  high  order. 

For  colours  have  much  meaning  in  the  flower  Ian- 


The  Golden  Rule  for  Flowers          225 

guage,  and  show  to  some  considerable  extent  what 
kind  of  insects  are  wanted  for  the  blossoms  which 
display  them. 

White,  for  instance,  serves  to  attract  insects  of  all 
sorts  ;  but  bright  yellow  seems  to  be  especially  favoured 
by  beetles,  and  blue  by  bees,  though  they  do  not,  of 
course,  confine  themselves  to  flowers  of  this  or  any 
colour.  What  a  flower  lacks  in  colour  may  often  be 
more  than  made  up  for  by  its  sweet  scent  and  abound- 
ing nectar.  The  dull  pink  sedum,  for  instance,  which 
blossoms  in  the  autumn,  attracts  a  swarm  of  humble- 
bees  and  butterflies  ;  though,  as  its  flowers  are  flat  and 
tubeless,  the  nectar  is  open  to  all  comers,  and  bees  are 
not  necessary  to  it. 

Yellow  is  said  to  attract  insects  of  the  lowliest  kind ; 
white,  those  a  little  higher  in  the  scale ;  and  pink,  red, 
lilac,  purple,  blue,  rank  higher  and  higher  as  to  the 
insects  which  they  attract,  that  very  superior  insect, 
the  bee,  being,  as  already  said,  especially  pleased  with 
blue. 

It  is  the  fashion  at  present  to  say  that  the  bright 
colours  and  sweet  scents  of  flowers  exist  solely  for  the 
plant's  own  benefit,  as  the  means  of  drawing  to  it 
the  insects  which  carry  pollen  from  one  blossom  to 
another.  Nevertheless,  man  is  gratified  abundantly; 
and  if  this  theory  be  correct,  he  may  at  least  congra- 
tulate himself  on  the  fact  that  he  and  the  insect- 
world  are  of  one  mind  as  to  what  is  agreeable  and 
attractive. 

But  are  he  and  they  altogether  of  one  mind  ?  The 
butterfly  will  hover  about  a  lavender-bush,  attracted  by 
the  perfume,  and  so  far  man  shares  its  taste;  but  it 
will  also  go  and  drink  daintily  at  a  drain,  and,  for  any* 


226  The  Golden  Rule  for  Flowers 

thing  that  appears  to  the  contrary,  an  ill  scent  may  be 
as  pleasant  to  it  as  a  sweet  one. 

Ill-smelling  flowers,  as  well  as  sweet  ones,  have  their 
admirers,  and  are  certainly  not  especially  avoided  by 
insects  ;  and  flies  will  regale  themselves  upon  honey  or 
filth,  with  apparently  equal  satisfaction.  Ill-smelling 
flowers  are,  however,  comparatively  very  few ;  and  as 
their  colours  are  generally  deep  yellow,  orange,  brown- 
red,  or  brown,  we  may  conclude  that  they  are  not 
frequented  by  such  high-class  insects  as  bees. 


XVI. 

GUESTS  WELCOME  AND   UNWELCOME 

BEES  do  more,  on  the  whole,  for  the  fertilization  of 
flowers  than  any  other  insects ;  but,  though  plentiful 
throughout  the  plains  of  Europe,  they  become  fewer 
and  fewer  as  the  traveller  ascends  the  Alps  ;  and  in  the 
Tyrol,  at  a  height  of  from  6,000  to  9,000  feet,  he  may 
see  hardly  so  much  as  a  bee  a  day,  and  that  of  the 
'  humble '  species  only. 

There  is,  it  is  true,  the  Ligurian,  or  yellow  Alp-bee, 
which  is  a  mountain  insect,  and  thrives  in  some  of  the 
southern  cantons  of  Switzerland  up  to  a  height  of 
4,500  feet ;  but  still,  the  higher  one  goes  the  fewer  bees 
there  are  of  any  kind;  and  though  there  are  many 
beetles  and  flies,  and  very  many  moths  and  butterflies, 
there  are,  on  the  whole,  fewer  insects  of  all  kinds  in 
these  higher  regions;  and  in  the  highest,  bees  are 
almost  entirely  absent. 

Yet  the  flowers  of  the  high  Alps  are  so  intensely 
bright  in  colour  that  it  is  pretty  certain  they  must  be 
visited  by  insects  of  some  sort ;  and,  besides  being  of 
such  vivid  colours,  the  flowers  here  are  made  still  more 
striking  by  being  massed  together  in  large  beds,  instead 
of  being  scattered  here  and  there.  For  the  fewer  the 


228         Guests   Welcome  and  Unwelcome 

insects,  the  more  needful  it  is  to  economize  their  time 
and  labour,  and  to  avoid  the  risk,  which  solitary  plants 
would  run,  of  being  overlooked  altogether.  Here,  as 
elsewhere,  '  union  is  strength ';  and  the  butterfly  must 
be  blind  indeed  which  could  fail  to  notice  these  masses 
of  brilliant  colour. 

For  the  chief  flower-visitors  in  these  Alpine  regions 
are  moths  and  butterflies,  together  with  flies  and 
beetles  ;  and  it  is  curious  to  see  how  flowers  which  are 
visited  by  bees  in  the  plains  and  lower  mountain- 
regions  are  modified  to  suit  moths  or  butterflies  when 
they  come  up  higher. 

Of  the  many  orchids,  for  instance,  which  grow  in  the 
plains,  all  but  very  few — four  or  five,  perhaps — are 
visited  by  bees  ;  but  in  the  Alps,  out  of  five  species,  all 
but  one  or  two  are  dependent  upon  butterflies  or 
moths. 

Flowers  change  in  colour  when  they  migrate  to 
these  higher  regions,  on  purpose  to  attract  more  notice 
Our  pale  yellow  primrose  is  fertilized  almost  entirely 
by  moths,  but  it  might  be  overlooked  among  the  bright 
flowers  of  the  Alps  if  it  did  not  dress  more  gaily  there, 
so  it  wears  brilliant  pink  and  magenta.  The  wild  pinks 
also,  which  straggle  about  here  and  there  in  the  low- 
lands, sure  not  to  escape  notice  among  the  many 
visitors  constantly  flitting  to  and  fro,  here  take  the 
precaution  of  growing  larger  blossoms,  besides  massing 
themselves  together  in  such  a  way  as  to  catch  the  eye 
of  any  wandering  insect. 

Large  masses,  large  blossoms,  brilliant  colours— 
these  are  the  means  by  which  the  fewer  insects  of  the 
high  Alps  are  guided  without  loss  of  time  to  the  place 
where  they  are  wanted ;  and  flowers  which  might  never 


Guests   Welcome  and  Unwelcome 

be  found  out  if  they  grew  separately  are  ensured  against 
neglect  by  thus  growing  in  company. 

But,  many  and  beautiful  as  are  the  moths  and  butter- 
flies of  the  mountains,  one  must  go  to  the  tropics  to 
see  them  in  their  full  glory  of  numbers,  size,  and 
colouring. 

Of  all  parts  of  the  world,  South  America  is  richest  in 
butterflies,  and  the  richest  part  of  South  America  is 
the  region  of  the  Amazons;  where,  also,  the  broad 
belt  of  forest  which  surrounds  the  land-surface  of  the 
earth  almost  continuously  at  the  equator  is  denser 
than  anywhere  else,  and  swarms  with  insects  of  many 
kinds. 

There  are  some  1,200  species  of  butterflies  in  this 
region ;  but  these  gay  insects  do  not  care  for  the 
solemn  depths  of  the  forest,  where  they  find  little  or 
no  entertainment,  and  they  are  chiefly  to  be  seen  in 
the  more  or  less  open  paths,  where  there  is  more  light, 
and  where,  consequently,  more  flowers  are  to  be  found. 

Here  large  blue  butterflies,  and  many  others,  fly  along 
for  miles,  and  always  return  if  driven  into  the  forest. 
For  this  is  gloomy  and  even  musty,  like  a  cavern  ;  the 
damp  ground  is  not  covered  by  herbage,  there  is  little 
beauty  or  brilliancy  of  colouring  in  the  trees,  and 
flowers  are  rare. 

The  fact  is  that,  according  to  the  German  proverb, 
'  one  cannot  see  the  forest  for  the  trees.'  They  are  so 
crowded  together,  and  they  run  up  to  such  a  height, 
that  there  is  little  to  be  seen  but  trunks,  canopied  by 
a  mass  of  foliage  so  dark  and  dense  that  the  sun  is 
quite  powerless  to  penetrate  it. 

Many  trees  never  blossom  until  they  are  a  hundred 
feet  high,  and  it  is  only  when  a  shower  of  bright  petals 


230         Guests  Welcome  and  Unwelcome 

falls  from  above  that  there  is  any  sign  of  what  is  going 
on  overhead,  or  of  the  beauty,  displayed  to  insects 
only,  outside  the  dark  canopy.  Beneath  it  the  world  is 
dank,  dull,  gloomy,  unrelieved  by  a  ray  of  light ;  but 
what  a  different  world  it  is  above  !  Here  the  sun  is  in 
full  blaze,  and  bees  in  swarms  are  humming  cheerily 
over  the  magnificent  banquet  of  flowers  spread  for 
them. 

Bees  do  not  like  gloom,  or  even  the  chequered  shade 
which  contents  the  butterflies,  and  they  would  have 
missed  the  feast  if  the  flowers  had  grown  down  below. 

It  is  by  the  roadside,  on  the  margin  of  the  forest,  in 
the  paths,  and  along  the  river-banks  that  the  real 
beauty  of  tropical  vegetation  is  to  be  seen ;  for  here 
are  bushes,  shrubs,  trees  of  every  height,  adorned  with 
festoons  of  creepers,  and  brilliant  with  bright  flowers 
and  gorgeous  butterflies. 

Even  here,  however,  there  is  nothing  to  surpass  such 
masses  of  glorious  colour  as  are  to  be  seen  on  our 
heathery  moors  or  gorse-covered  commons ;  and  though 
tropical  blossoms  are  undoubtedly  splendid,  they  are 
not  as  common  as  one  is  apt  to  fancy,  and  they  gene- 
rally last  but  a  short  time,  beginning  to  fall  almost  at 
once. 

Bees  abound  in  this  region,  but  they  keep  in  the 
sun,  among  the  blossoms  borne  high  up  overhead ;  and 
the  butterflies  float,  lazily  along  the  paths  which  are 
chequered  with  light  and  shade,  but  they  keep  for  the 
most  part  near  the  ground.  If  the  smaller  trees,  there- 
fore, followed  the  example  of  the  giants  of  the  forest, 
and  bore  their  blossoms  on  their  tops,  they  would  be  in 
danger  of  missing  both  classes  of  visitors.  The  bees 
would  know  nothing  about  them  down  in  the  shade, 


Guests   Welcome  and  Unwelcome        231 

and  the  butterflies  would  not  rise  high  enough  to  find 
them. 

Under  these  circumstances,  therefore,  many  trees, 
such  as  the  custard-apple,  bear  their  blossom  on  the 
trunks  or  larger  branches,  where  moths  and  butterflies 
can  find  them.  The  cacao  is  another  which  does  so, 
and  when  the  large  yellow  fruit  is  ripe,  the  trunks  of 
some  of  the  smaller  trees  are  hardly  to  be  seen,  so 
thickly  does  it  cover  them. 

But,  much  as  these  insects  do  both  in  the  tropics 

and   in  the  mountains,  it  must  not 

be  supposed  that  their  services  could 

be  dispensed  with  even  in  temperate 

latitudes  and  in  the   plains.     Quite 

the  contrary.    Most  of  the  European 

orchids   are   fertilized   by  bees,  but 

just   a  few  species   cannot   get    on 

without  the  help  of  moths.     There 

is  a  large  sphinx-moth  which  carries 

pollen  to  and  from   one  species  of 

orchid  in  a  very  curious  way — on  its 

eyes.     The    pollen    of    this    flower 

grows  in  two  masses,  each  perched 

upon  a  stalk  which  passes  through  its  centre,  and  to 

which  the  grains  are  united.     At  the  base  of  the  stalks 

are  tiny  button-shaped  discs,  one  on  each  side  of  the 

stigma,  face  to  face.     When  the  moth  presses  its  head 

into   the   centre  of  the  flower,  the   discs   come   into 

contact   with   its   eyes,  and,  being  very   sticky,   they 

adhere  so  firmly  that  the  whole  thing  is  dragged  out 

— stalk,  pollen,  and  all.     A  very  strange  object  one  of 

these  moths  is  when  it  is  thus  adorned,  for  the  stalks, 

with  their  lumps  of  pollen  at  the  end,  at  first  stand  out 


232         Guests   Welcome  and  Unwelcome 

straight,  like  horns  in  the  wrong  place.  In  a  minute 
or  so,  however,  they  contract  and  bend  down,  and  then 
the  pollen  is  in  exactly  the  right  position  to  be  caught 
and  held  by  the  stigma  of  the  next  blossom  of  the 
same  species,  which  the  insect  must,  one  would 
imagine,  be  in  haste  to  enter  if  it  knows  how  it  may 
get  rid  of  its  undesirable  appendages. 

Orchid-blossoms  remain  in  full  beauty  a  long  time, 
whether  cut  or  not,  as  long  as  they  are  not  fertilized  ; 
but  when  insects  are  allowed  to  get  at  them,  they  fade 
rapidly  and  go  to  seed. 

Among  the  flowers  specially  attractive  to  moths  in 
Europe  are  the  valerian,  petunia,  phlox,  hop,  nettle, 
pink,  ivy,  clematis,  pansy,  jessamine,  and  honeysuckle, 
the  last  being  frequented,  according  to  Gilbert  White, 
by  a  large  sphinx-moth,  which  appears  after  dusk,  and 
feeds,  like  the  humming-bird,  on  the  wing,  scarcely 
ever  settling,  and  making  a  humming  noise  with  its 
wings. 

The  jessamine  is  probably  fertilized  by  the  hawk- 
moth,  which  hovers  in  like  manner;  but  jessamine-seed 
is  rare  in  England,  for  hawk-moths  are  rare  too.  But 
the  want  of  hawk-moths  may  not  be  the  sole  reason 
for  the  scarcity  of  seed.  The  humble-bees  are  also  in 
some  measure  to  blame,  for  they  come  to  the  blossoms 
in  search  of  nectar,  and  finding  no  perch  upon  which 
they  can  stand  to  suck  in  the  proper  way — the  only 
way  to  benefit  the  flower — they  get  what  they  want 
by  gnawing  through  the  tube  of  the  corolla,  which 
soon  drops  in  consequence. 

Flowers  which  open  at  night  are  of  course  especially 
dependent  upon  night-flying  moths ;  and  as  colours 
would  not  be  seen,  they  are  generally  white  or  pale 


Guests  Welcome  and  Unwelcome        233 

yellow,  and  have  no  lines  to  show  where  the  nectar  is, 
for  these  also  would  not  be  visible ;  but  they  are  often 
so  sweet  as  to  be  scented  from  afar.  The  large  white 
bindweed,  though  it  opens  by  day,  remains  open  at 
night,  when  the  moon  shines,  but  not  otherwise,  to  receive 
the  visits  of  moths. 

Wherever,  in  any  part  of  the  world,  there  is  a  dearth 
of  bright-coloured  flowers,  there,  as  a  rule,  there  is  a 
scarcity  of  insects,  and  vice  versa,  for,  where  insects 
are  wanting,  there  the  flowers  fertilized  by  them  cannot 
of  course  flourish. 

The  scarcity  of  both  these  is  very  conspicuous  in  the 
Galapagos  islands,  situated  on  the  equator,  some  700 
miles  west  of  South  America.  In  Juan  Fernandez  also, 
which  lies  about  400  miles  off  Chili,  ferns  form  the 
larger  part  of  the  vegetation,  as  they  do  in  most  of 
the  South  Sea  islands.  But  there  is  no  such  total 
absence  of  showy  blossoms  in  Juan  Fernandez  as  in  the 
Galapagos.  One  shrub  which  flourishes  there  bears 
snowy  blossoms,  like  those  of  the  magnolia ;  another, 
also  plentiful,  has  dark  blue  flowers  ;  and  besides 
these,  there  are  large  patches  of  a  white,  lily-like  bulb, 
and  there  are  two  conspicuous  yellow  flowers  as  well. 

Yet  Juan  Fernandez  is  poor  in  insects.  It  has  but 
one  butterfly,  and  that  is  rare;  there  are  only  four 
species  of  moths,  and  no  bees  at  all,  but  some  which 
are  very  minute  and  of  no  more  use  to  large  blossoms 
than  the  flies,  of  which  there  are  twenty  species. 

But  the  poverty  of  the  insect-life  is  made  up  for  by 
the  presence  of  humming-birds,  which  are  so  abundant 
that  there  are  one  or  two  in  every  shrub ;  and  these 
when  killed  are  usually  found  with  the  front  of  their 
heads  covered  with  pollen. 


234         Guests   Welcome  and  Unwelcome 

The  group  of  honey-eating  birds  is  so  immense,  both 
in  the  islands  of  the  Pacific,  Australia,  America — North 
and  South — the  Moluccas,  etc.,  that  there  can  be  no 
doubt  as  to  the  large  share  they  take  in  conveying 
pollen  from  one  flower  to  another. 

The  ruby-throated  humming-bird  frequents  lilacs, 
phloxes,  portulaccas,  morning  glories,  roses,  honey- 
suckles, snap-dragons,  fuchsias,  and  many  other  flowers; 
and  in  dry  weather,  before  the  spring  begins,  it  will 
even  enter  greenhouses  and  suck  the  fuchsias  there, 
which  it  does  more  rapidly  than  the  honey-bee. 

The  Portuguese  name  for  the  humming-bird  is 
Beija  Flor,  *  Kiss-flower';  but  the  little  creature  is 
not  so  ethereal  in  its  habits  as  its  appearance  and 
poetical  name  have  led  people  to  suppose.  It  does 
'  kiss  '  the  flowers,  but  with  a  view  to  something  more 
substantial  than  nectar  merely,  though  that  may  be  all 
very  well  as  an  addition  to  its  food. 

Many  a  humming-bird  has  been  starved  to  death  in 
captivity,  owing  to  the  mistaken  notion  that  honey, 
or  sugar-and-water,  was  all  that  it  needed;  whereas 
these  living,  flashing  jewels  possess  tongues  which  are 
exactly  adapted  for  picking  up  insects ;  and  insects  are 
their  principal  food,  though  they  take  nectar  as  well. 

The  humming-bird's  tongue  is  long,  and  can  be 
stretched  out  far  beyond  its  bill ;  it  is  very  flexible,  and 
being  cleft  in  two  it  can  be  opened  and  shut  at  will, 
'  like  a  delicate,  pliable  pair  of  forceps.' 

The  humming-bird  is,  indeed,  nearly  related  to  the 
swift,  and  its  chief  diet  consists  of  the  small  insects 
which  are  seldom  wanting  in  the  long-throated 
blossoms  of  the  tropics.  The  sheaths  of  the  arums 
and  their  kindred  are  generally  full  of  insects  too ;  so 


Guests  Welcome  and  Unwelc<*me         235 

are  those  of  the  palms,  and  the  '  pitchers  '  with  which 
many  plants  are  furnished  likewise  afford  insects  in 
abundance. 

Whether  the  birds  go  for  nectar  or  for  insects,  it  is 
all  the  same  so  far  as  the  plant  is  concerned,  for  in 
neither  case  can  they  help  coming  in  contact  with  the 
stamens  and  getting  their  heads  and  beaks  dusted  with 
pollen. 

The  Marcgravia,  for  instance,  is  a  plant  which  grows 
a  circle  of  flowers  like  the  lamps  of  an  inverted  can- 
delabrum. From  the  centre  of  tr.'S  circle  hang  a 
number  of  pitchers  filled  with  a  sweet  »h  liquid,  which 
attracts  swarms  of  insects.  These,  n  their  turn, 
attract,  not  only  humming-birds,  but  a  variety  of 
others  which  cannot  capture  their  prey  without  brush- 
ing against  the  hanging  stamens  of  the  bell-flowers. 

In  Labuan  large  flocks  of  starlings  are  similarly 
attracted  to  a  flower  with  brilliant  scarlet  blossoms ; 
and  in  the  Malay  and  Molucca  Islands  much  pollen- 
carrying  is  done  by  the  little  brush-tongued  lories, 
small  parrots,  with  unparrot-like  tongues,  which  are 
long,  flexible,  moist  and  hairy,  and  thus  well  adapted 
for  collecting  honey  from  the  tubes  of  the  many  large 
blossoms  which  they  visit. 

Bees,  butterflies,  moths,  birds — these  are  the  most 
conspicuous  of  the  '  under-gardeners,'  to  whom  is  en- 
trusted the  important  work  of  fertilization ;  but  there 
are  others  equally  useful  in  their  way,  though  their 
sphere  of  operations  is  less  extensive.  Even  the  wasps 
do  something,  for,  in  the  absence  of  fruit,  they  suck 
flowers,  as  Gilbert  White  remarked,  especially  those  of 
the  ivy  and  small  umbelliferous  flowers;  they  are 
especially  attracted  by  the  red  and  yellow  blossoms  of 


236         Guests  Welcome  and  Unwelcome 

the  '  Poker-plant '  (Tritoma),  which  blossoms  in  the 
late  summer,  and  may  be  seen  creeping  quite  into  the 
tubes;  and  they  are  also  said  to  fertilize  the  dahlia, 
which  is  shunned  by  bees. 

'  Where  the  bee  sucks  honey  the  wasp  sucks  poison/ 
is  a  common  saying,  and  as  devoid  of  foundation  as 
such  sayings  often  are.  It  is  a  libel  on  the  wasp,  and 
too  flattering  for  the  bee ;  for  if  the  bee  does  suck  and 
store  honey,  which  last  the  wasp  does  not  pretend  to 
do,  it  also  secretes  poison,  and  its  sting  is  generally 
considered  much  the  worse  of  the  two ! 

To  small,  flat  flowers,  whose  nectar  lies  so  near  the 
surface  as  to  require  little  probing  for,  beetles  and 
small  flies  are  almost  as  useful  as  bees,  and  may  be 
seen  in  crowds  on  such  little  blossoms  as  those  of  the 
wild  carrot,  and  others  of  the  same  family  which  grow 
together  in  flat  heads  or  umbels.  Even  the  water-side 
midges  do  their  part  among  the  small  flowers  of  the 
river  banks. 

All  sorts  of  little  flies,  gnats  and  midges  are  attracted 
also  to  the  arums,  some  by  the  prospect  of  pollen  and 
nectar,  others,  as  the  carrion-flies,  by  the  flesh-like 
appearance  and  smell  of  many  foreign  species,  on 
which  they  even  lay  their  eggs,  supposing  that  their 
grubs  will  be  well  fed;  another  illustration  of  what 
was  said  before,  that  if  they  existed  solely  for  the 
purpose  of  attracting  insects,  all  flower  scents  might 
just  as  well  be  what  human  beings  consider  disagree- 
able. 

The  arrangements  of  the  arum  family  are  so  curious 
as  to  be  worth  a  little  special  attention.  We  most  of 
us  know  the  so-called  '  arum-lily,'  with  its  white  flower 
with  the  golden  sceptre.  The  flowers  of  the  arum  are 


Guests  Welcome  and  Unwelcome        237 

contained  in  a  sheath,  properly  called  a  spathe,  which 
is  snowy  white  in  the  '  arum-lily '  and  greenish  in  the 
wild  one.  The  real  blossoms  are  clustered  round  the 
sceptre,  or  spadix,  which  is  golden  in  the  one,  and 
purplish,  or  brown,  in  the  other. 

In  some  of  the  southern  and  foreign  arums  the  lower 
part  of  the  sheath,  which  is  enlarged  and  contains  the 
blossoms,  is  shut  off  by  a  ring  of  longish  hairs  which 
point  downwards  and  allow  the  visitors  to  enter  easily, 
but  effectually  prevent  their  coming  out  again  until 
they  have  done  what  is  wanted  of  them.  The  lower 
part  of  the  spadix  generally  bears  the  flowers  with 
pistils,  those  with  stamens  being  arranged  in  a  ring  a 
little  above.  The  lower  blossoms  are  ready  first,  and 
to  them  the  insects,  or  some  of  them,  bring  pollen  from 
other  flowers  of  the  same  species.  But  it  is  not  enough 
for  them  to  bring  pollen,  they  must  also  carry  some 
away,  and  for  this  purpose  they  must  be  kept  until  the 
anthers  burst. 

Meanwhile  their  prison  is  made  very  comfortable  for 
them  :  it  is  pleasantly  scented — we  are  not  speaking 
now  of  the  fleshy  species — it  is  also  warmed  and  pro- 
vided with  nectar.  When  the  anthers  burst,  pollen  is 
added  to  the  feast,  and  some  of  the  captives  devour  it 
so  greedily  as  to  be  quite  intoxicated.  Enough,  how- 
ever, remains  adhering  to  their  legs  and  bodies  to  make 
them  acceptable  visitors  elsewhere,  and,  as  soon  as  the 
pollen  is  shed  and  there  is  no  further  reason  for  keep- 
ing them,  the  hairs  which  prevented  their  escape 
wither  and  die,  and  they  are  free  to  depart — generally, 
but  not  always.  The  hairy  arum  of  the  South  is  said 
to  show  her  gratitude  for  the  services  rendered  to  her 
by  her  visitors,  carrion-flies,  in  a  remarkable  manner. 


238         Guests   Welcome  and  Unwelcome 

She  catches  and  devours  many,  digesting  them  by 
means  of  the  sticky  hairs  which  cover  the  inside  of  the 
sheath. 

Most  of  the  arums  of  the  temperate  zones  blossom 
early  in  the  year,  when  the  nights  are  still  chilly 
enough  to  make  the  prospect  of  a  warm  lodging 
attractive. 

Blossoms  breathe  more  rapidly  than  leaves,  and  are 
always  therefore  a  little  the  warmer.  Buds  just  open- 
ing breathe  so  fast,  if  they  are  large,  like  those  of  a 
cucumber,  that  when  they  are  isolated  under  a  glass 
containing  a  tiny  thermometer,  the  mercury  may  be 
seen  to  rise  sometimes  nearly  two  degrees. 

Many  blossoms  heat  so  much  more  than  this,  how- 
ever, that  the  difference  may  be  felt  as  well  as  seen. 
This  is  the  case  with  the  arums,  whose  so-called 
blossom  is  really  an  assemblage  of  many  blossoms. 
In  the  common  wild  arum,  '  lords  and  ladies,'  the  tem- 
perature rises  several  degrees,  but  in  the  heart-leaved 
arum  of  the  Isle  of  Bourbon  the  temperature  of  the 
sceptre,  or  spadix,  has  been  known  to  rise  to  95°  F., 
and  nearly  102°  F.,  and  that,  too,  when  the  temperature 
of  the  air  was  only  59*  F. 

But  the  common  Italian  arum  outdoes  even  its 
tropical  cousin,  and  its  spadix  becomes  hotter  than  a 
hot  bath,  its  temperature  being  nearly  110°  F. 

Arums  are  especially  marsh-plants,  and,  though  one 
does  not  naturally  associate  the  idea  of  warmth  with 
such  cold  creatures  as  snails,  it  seems  that  it  is  these 
which  are  chiefly  attracted  to  the  arums  of  south 
Europe,  and,  no  doubt,  of  other  parts  of  the  world. 

One  of  the  foreign  arums  grown  in  hot-houses  for 
the  sake  of  their  handsome  foliage  was  observed  one 


Guests  Welcome  and  Unwelcome        239 

day  at  noon  to  begin  to  blossom  and  grow  warm  at 
the  same  time,  its  temperature  rising  beyond  100°  F. 
Suddenly  it  gave  out  a  strong  fragrant  scent,  between 
that  of  cinnamon  and  musk,  which  filled  the  whole 
house,  and  would  no  doubt  have  been  a  well-under- 
stood signal  in  its  own  country,  telling  the  small 
marsh-snails  that  their  night  quarters  were  ready. 
These  would  climb  the  stalk  and  find  entrance  by  a 
narrow  opening  at  the  base  of  the  sheath,  which  would 
soon  after  close  upon  them.  Twenty- four  hours  later 
the  scent  and  warmth  have  much  diminished,  but  then 
the  anthers  open  and  drop  down  their  pollen,  not  in 
separate  grains,  but  in  chains  or  tassels  of  grains 
adhering  together,  as  much  as  an  inch  long,  and  far  too 
bulky  therefore  to  be  carried  away  by  insects.  On 
coming  in  contact  with  the  moist  bodies  of  the  snails, 
however,  the  chains  separate  into  grains,  which  adhere 
and  are  borne  away  when  the  guests  move  on. 

And  they  are  obliged  to  move  on  soon  after  the 
pollen  has  fallen  or  else  they  would  be  suffocated  ;  for 
the  blossoms  have  been  breathing  vigorously  in  a  con- 
fined space,  and  so  much  carbon  has  been  burnt,  and 
so  much  carbon-dioxide  produced,  that  the  bulb  of  the 
sheath  is  completely  filled  with  it,  and  a  glowing  match 
held  within  is  extinguished.  Such  visitors  as  stay  too 
long  are  therefore  safely  suffocated,  and  thus  prevented 
from  eating  the  young  fruit,  which  they  would  other- 
wise do  without  fail. 

The  prudent  snails,  however,  having  enjoyed  their 
warm  bed  and  nectar,  do  not  outstay  their  welcome ; 
but,  when  these  passing  pleasures  have  come  to  an 
end,  they  linger  no  longer,  make  the  best  of  their  way 
up  the  sheath  and  down  the  long  stem,  and  then 


24 o         Gziests   Welcome  and  Unwelcome 

proceed  without  delay  to  climb  some  other  plant 
whose  blossoms  are  beginning  to  give  fragrant  notice 
that  another  pleasant  guest-chamber  is  ready  for  their 
reception.  Thanks  to  this  diligence,  therefore,  pollen 
is  brought  to  the  pistils,  as  soon  as  they  are  ready  for 
it,  by  the  '  fastest  snail-express.' 

Hitherto  we  have  confined  our  attention  to  the 
welcome  guests ;  but  there  are  unwelcome  ones  also, 
and  the  very  snails  last  considered  have  two  sides  to 
their  character.  Indeed,  the  beneficent  side  is  not  the 
one  with  which  we  are  familiar,  being  rather  a  recent 
discovery,  while  their  mischievous  propensities  are 
well  and  widely  known.  Even  the  arums  which 
welcome  them  as  pollen-carriers  need  some  sort  of 
protection  against  them.  They  have  to  be  tempted 
to  undertake  what  to  them  is  really  an  immense 
journey,  by  special  attractions,  otherwise,  being 
voracious  eaters,  they  would  simply  begin  to  devour 
the  first  leaf  they  came  across.  Then,  when  they  have 
started,  all  loitering  by  the  way  is  sternly  discouraged, 
for  arum-leaves  are  acid,  and  even  poisonous ;  so  there 
is  no  temptation  to  make  a  meal  of  them. 

Useful  as  they  are  to  arums  and  arum-like  plants, 
they  are  not  generally  desirable  as  visitors,  and  are  not 
often  found  in  flowers,  bristles  and  prickles  being 
enough  to  turn  them  back  at  once.  No  wingless 
visitors  are  generally  welcome,  for  they  crawl  slowly, 
lose  pollen  by  the  way,  by  getting  it  rubbed  off  them, 
and  are  usually  so  indiscriminate  in  their  tastes,  that 
they  go  as  readily  to  one  blossom  as  another,  and  it  is 
quite  a  chance  what  pollen,  if  any,  they  may  bring 
with  them. 


Guests   Welcome  and  Unwelcome         241 

It  is,  of  course,  not  to  the  plant's  interest  that  its 
pollen  and  nectar  should  be  taken  by  insects  which 
plunder  without  making  payment  in  return,  as  it  is 
thereby  robbed  of  its  means  of  attracting  other  and 
more  useful  insects.  But  the  useless  ones  are  just  as 
fond  of  nectar  as  the  useful,  just  as  quick,  too,  to  find 
it  out,  wherever  it  may  be  hidden,  so  that  many  devices 
are  needed  to  baffle  these  unwelcome  guests. 

Human  beings  can,  it  is  said,  detect  less  than  the 
twenty-millionth  part  of  a  grain  of  musk ;  but  in  keen- 
ness of  scent  they  are  far  surpassed  by  the  insect  world. 

Where  is  the  man  who  can  detect  any  difference, 
by  smell  or  otherwise,  between  cane-sugar  and  beet- 
sugar,  when  the  latter  is  properly  refined? — not,  of 
course,  such  as  one  meets  with  in  continental  hotels. 
Yet  the  bees  know  well,  for  if  the  choice  be  given 
them,  they  will  take  the  cane  and  leave  the  beet. 

And  ants  are  not  only  as  fond  of  sweets  as  bees, 
but  will  find  them  out  from  an  immense  distance. 
They  have  been  known  to  make  their  way  up  from  the 
garden  to  the  second  story  of  a  house,  by  means  of 
an  outside  bell-wire,  all  for  the  sake  of  some  dried 
fruit  which  they  had  scented  out.  They  are  sure, 
therefore,  to  know  where  nectar  may  be  had,  as  well 
as  the  bees  themselves ;  and  yet,  what  with  their 
crawling,  and  their  tidy  habit  of  constantly  cleaning 
themselves,  and  their  hard  coats,  which  are  not  suited 
for  carrying  pollen,  they  are  some  of  the  least  welcome 
guests  that  a  flower  can  have. 

When  the  ants  do  get  a  chance,  they  make  the 
most  of  it,  and  swarm  in  greedily ;  but  on  the  whole 
they  are  pretty  well  kept  out,  now  by  one  means,  now 
by  another, 

IS 


242         Guests   V/elcome  and  Unwelcome 

The  snap-dragon,  for  instance,  keeps  her  mouth  so 
firmly  closed  that  none  but  the  strong  humble-bee  can 
force  its  way  in,  until,  that  is,  the  necessary  pollen  has 
been  brought.  But  then,  when  the  seed  is  made  sure, 
and  the  ants  can  do  no  harm,  the  lips  are  unclosed, 
and  they  are  generously  admitted  to  what  remains  of 
the  feast,  an  opportunity  of  which  they  do  not  fail  to 
make  use. 

Ants,  like  other  wingless  insects,  prefer  to  avoid  the 
dew,  and  so  are  not  astir  very  early.  Some  flowers, 
therefore,  unfold  for  only  a  short  time  during  the  first 
hours  of  the  morning  and  close  again  by  9  a.m. ;  and 
in  all  probability  there  is  a  close  connection  between 
the  times  when  flowers  open  and  close,  and  the  hours 
when  their  friends  and  enemies  are  abroad. 

Plants  such  as  the  teasel  keep  off  the  ants  by  means 
of  the  basins  formed  by  their  leaves,  which  catch  the 
dew  as  it  trickles  down  their  stems,  and  keep  it  so 
effectually  as  to  be  seldom  empty  while  the  plant  is  in 
blossom.  Water  is  completely  baffling  to  ants,  and 
if  placed  on  the  stem  of  a  plant  thus  protected,  they 
run  helplessly  up  and  down,  and  then  drop  to  the 
ground. 

Stickiness,  too,  of  all  kinds,  is  their  abhorrence,  and 
is  often  fatal  to  them,  whether  in  the  form  of  sticky 
hairs  or  sticky  juice.  The  lettuce  is  one  of  many 
plants  furnished  with  a  milky  juice,  which  is  especially 
abundant  near  the  flowers.  If  an  ant  crawls  up  the 
stem,  its  hooked  feet  are  so  sharp  as  to  cut  through 
the  outer  skin,  and  the  juice  which  at  once  oozes  out 
hardens  rapidly,  gluing  it  to  the  spot,  while  the  little 
creature's  frantic  efforts  to  clean  itself  only  make 
matters  worse,  and  it  seldom  succeeds  in  escaping. 


Guests   Welcome  and  Unwelcome         243 

Many  of  the  plants  belonging  to  the  order  which 
contains  the  catch-flies,  campions  and  pinks,  are 
provided  with  rings  of  sticky  hairs,  and  as  many  as 
sixty-four  small  insects  have  been  found  at  once  on 
one  flower-stalk  of  the  red  German  catch-fly.  One 
can  imagine  how  little  nectar  would  have  been  left  to 
attract  profitable  insects,  if  these  sixty-four  had  been 
allowed  to  have  their  way.  Ants  are  usually  very  wary 
in  their  manner  of  proceeding,  and  feel  their  way 
carefully  up  the  stalk  until  they  reach  the  sticky  ring, 
whereupon  they  generally  turn  round  and  come  down 
again ;  but  if  they  do  venture  to  proceed  they  are 
surely  lost. 

Stickiness  is  no  impediment  to  slugs  and  snails, 
however,  for  they  overcome  it  by  covering  it  with  their 
own  slime.  What  they  do  mind  are  bristles  and 
prickles,  which  the  armour-clad  ant  can  afford  to 
despise. 

Pricklets,  hairs,  and  fringes  inside  the  blossom,  serve 
often  a  double  purpose,  for  they  both  keep  out  un- 
welcome visitors  and  make  the  welcome  ones  reach 
the  nectar  by  the  right  way.  Thus,  insects  wanting  to 
get  at  the  honey  in  the  spur  of  the  garden-nasturtium, 
are  obliged  to  climb  over  the  fringe  on  one  of  its  three 
lower  petals,  and  this  they  cannot  do  without  coming 
in  contact  with  anthers  or  pistil,  which  they  might 
otherwise  pass  untouched. 

Plants  sometimes  need  protection  against  even  their 
best  friends  the  bees,  for  some  of  these,  in  spite  of 
their  many  good  qualities,  have  a  way  of  trying  to 
reach  the  nectar  by  other  than  the  right  way — by 
house-breaking,  in  fact,  instead  of  by  the  front-door ; 
and  others,  though  willing  enough  to  come  in  properly, 


244         Guests  Welcome  and  Unwelcome 

are  too  small  to  be  serviceable  to  large  blossoms. 
We  have  already  mentioned  how  humble  -  bees  bite 
through  the  tube  of  the  jessamine,  because  they  find 
nothing  to  stand  upon  while  they  suck  the  blossom. 
But  as  the  jessamine  is  a  foreign  flower,  this  may  be 
thought  excusable  enough,  as  there  are  few  insects 
here  able  to  reach  the  nectar  in  the  right  way. 

But  some  bees  really  seem  to  be  lazily  inclined  to 
save  time  and  trouble,  for  they  always  bite  a  hole  in 
the  columbine,  among  others. 

The  bladder  campion,  however,  successfully  frus- 
trates any  such  designs  by  growing  a  calyx  which  is  so 
inflated  that  no  bee's  proboscis  is  long  enough  to  reach 
the  nectar  by  means  of  a  hole  made  in  it.  Others 
have  calyxes  so  hard  and  tough  that  even  humble-bees 
and  ants  are  baffled  by  them. 

But,  then,  the  little  bees — where  big  bees  can  enter, 
why  not  little  ones  ?  The  foxglove,  for  instance, 
gapes  widely  open;  and  as  stamens  and  pistil  lie 
close  under  the  upper  side  of  the  blossom,  they  are 
quite  out  of  the  way  of  the  small  bee,  which  would 
pass  in  and  out  without  touching  them,  if  it  were 
allowed  to  find  entrance  at  all.  But  an  observer  who 
watched  the  flowers  carefully  throughout  a  season  in 
North  Wales,  where  they  especially  abound,  saw  many 
small  bees  make  the  attempt  but  only  one  succeed 
the  whole  time.  It  looks  easy  enough,  but  the  upper 
part  of  the  blossom  is  so  smooth  as  to  be  actually 
slippery,  and  affords  no  foothold ;  and  the  lower  part 
is  beset  with  stiff  hairs,  which  are  very  embarrassing 
to  smaller  insects,  though  the  humble-bee  uses  them 
as  rests  for  her  feet  and  clings  to  them  while  she 
sucks, 


Guests  Welcome  and  Unwelcome        245 

It  is  interesting  to  watch  the  methodical  way  in 
which  a  humble-bee  visits  and  explores  a  spire  of  fox- 
glove, always  beginning  with  the  lowest  bell  and 
working  upwards  ;  but  it  may  not  have  occurred  to 
all  of  us  that,  if  she  reversed  her  operations,  the 
foxglove's  hope  of  cross-fertilization  would  be  gone. 
So  it  is,  however ;  for  the  foxglove-blossoms  not  only 
open  gradually,  beginning  with  the  lowermost,  but  the 
pollen  is  ripe  before  the  pistils  are  ready  for  it ;  and 
consequently  the  pistils  of  the  lower  blossoms  are 
waiting  for  pollen — their  own  being  safely  gone — 
while  the  anthers  of  the  upper  blossoms  are  dis- 
charging it.  If  the  bee  began  at  the  top,  she  would 
only  bring  to  the  pistils  pollen  from  the  upper  blos- 
soms on  the  same  stalk;  whereas,  leaving  off  at  the 
top,  she  carries  pollen  away  to  the  lowest  blossoms 
on  the  stem  of  another  plant. 

Such  are  a  few,  and  only  a  few,  of  the  many  marvel- 
lous provisions  for  ensuring  fertilization,  for  preventing 
self-fertilization,  for  promoting  cross-fertilization,  and 
for  preventing  the  robbery  of  pollen  and  nectar  by 
insects  which  would  not  benefit  the  plant ;  and  to 
conclude  with  the  words  of  Professor  Asa  Gray : 

'  If  these  structures  and  their  operations  do  not 
argue  intention,  what  stronger  evidence  of  intention 
in  nature  can  there  possibly  be  ?  If  they  do,  such 
evidences  are  countless,  and  almost  every  blossom 
brings  distinct  testimony  to  the  existence  and  pro- 
vidence of  a  Designer  and  Ordainer,  without  whom, 
we  may  well  believe,  not  merely  a  sparrow,  not  even  a 
grain  of  pollen,  may  fall.' 


XVII. 

SEED  -  SCATTERING 

THE  great  end  of  a  plant's  life  is  to  bear  fruit.  It 
is  for  this  that  roots  and  leaves  collect  nourishment, 
and  that  insects  and  birds  are  attracted  to  the  blos- 
soms by  bright  colours  and  the  prospect  of  food. 
So  entirely,  indeed,  is  fruit-bearing  the  aim  of  the 
plant's  life,  that  many  plants  are  dry  and  withered  by 
the  time  the  fruit  is  ripe,  having  given  up  all  their  sap, 
their  very  life,  to  bring  it  to  perfection.  In  any  case, 
whether  it  last  for  one  year  or  two,  or  many,  the 
plant's  life  is  devoted  to  making  preparation  for  its 
offspring. 

For  this  reason  few  wild  flowers  are  double,  as  the 
number  of  petals  must  be  increased  at  the  expense  of 
stamens  and  pistils,  and  without  these  fruit  is  im- 
possible. 

A  cherry-tree  covered  with  double-blossoms  may  be 
very  ornamental,  but  the  gardener  grows  it  for  its 
blossoms  only,  and  does  not  expect  fruit  from  it. 
When  his  object  is  fruit,  however,  he  sometimes 
interferes  in  another  way,  which  has  the  same  result, 
so  far  as  the  plant  is  concerned ;  for  he  increases  the 
eatable  part  of  the  fruit,  in  some  cases,  as  he  increases 
the  number  of  the  petals — at  the  expense  of  the  seed. 


Seed-  Scattering  247 

A  plant's  fruit  is  the  ripened  ovary,  containing  the 
seed ;  and  when  the  seed  is  the  part  used  for  food, 
man  naturally  devotes  his  attention  to  that,  and  cares 
nothing  for  the  case.  From  corn,  for  example,  and 
from  nuts,  he  wants  the  seed,  not  the  husk  or  shell, 
and  therefore  he  cultivates  and  increases  the  size  of 
the  seeds.  But  the  seeds  of  pears,  grapes,  pine-apples, 
oranges,  dates,  are  not  what  he  wants ;  and  in  some 
of  the  best  sorts  of  all  these  he  has  so  cultivated  the 
ovary,  or  fleshy  envelope,  at  the  expense  of  the  seeds, 
that  these  have  almost,  if  not  quite,  disappeared. 

He  has  done  much  the  same  thing,  too,  with  some 
of  the  best  figs ;  only  here  he  cares  neither  for  seed 
nor  ovary,  but  for  the  receptacle ;  for  a  fig  may  be  best 
described  as  being,  like  a  strawberry,  turned  outside  in. 

We  may  have  seen  young  figs  growing  on  the  trees 
in  plenty,  but  who  ever  saw  a  fig-tree  in  blossom  ? 

The  first  things  to  make  their  appearance  on  the 
leafless  branches  in  spring  are  not  buds  but  miniature 
figs. '  They  have  much  the  appearance  of  hard  green 
buds,  but  are  in  truth  stems,  hollowed  out,  and  having 
blossoms  ranged  round  them  inside,  each  pistillate 
blossom  having  its  own  ovary,  which  ripens  into  a 
minute  nut — the  true  fruit.  The  stem  or  receptacle, 
therefore,  is  the  part  which  becomes  sweet  and  fleshy, 
and  it  contains  within  it  many  ovaries,  just  as,  in 
the  case  of  the  strawberry,  many  ovaries  are  placed 
up  on  the  receptacle.  When  the  gardener  increases  the 
size  of  the  receptacle,  then,  and  diminishes  or  does 
away  with  the  '  seeds,'  he  grows  little  if  any  fruit, 
though  plenty  of  figs. 

The  fig  is  a  tree  nearly  related  to  the  mulberry,  hop, 
hemp,  and  stinging-nettle,  none  of  which  bear  pistils 


248  Seed-Scattering 

and  stamens  in  the  same  blossom ;  while  some,  as  the 
hop,  bear  them  on  different  plants. 

In  the  fig-tree  the  two  kinds  of  blossom  are  borne 
sometimes  in  the  same  '  fig, '  sometimes  on  separate 
trees.  In  the  former  case  the  pollen-blossoms  are 
above  and  the  ovule-blossoms  below,  and  there  would 
seem  to  be  no  difficulty  about  the  fertilization.  As  we 
have  already  mentioned,  fertilization  is  not  absolutely 
necessary  to  ensure  the  swelling  of  the  figs,  in  the  case 
of  some  varieties  at  all  events ;  but  still  many  growers 
resort  to  what  is  called  caprification,  in  order  to  ensure 
their  crop.  That  is  to  say,  they  take  branches  of  the 
wild  fig,  when  its  blossoms  are  ready,  and  place  them 
over  the  cultivated  fruit.  The  wild  fig  is  very  much 
frequented  by  a  small  insect,  which  deserts  the  wild  for 
the  cultivated  fig  as  soon  as  it  gets  its  wings.  Figs  are 
not  entirely  closed  at  the  top,  and  through  the  small 
opening  left  the  insect  makes  its  way,  for  the  purpose, 
probably,  of  laying  its  eggs.  Whether  it  carries  pollen 
from  the  wild  fig  or  from  the  staminate  blossoms  to 
those  below  it  in  the  same  fig,  or  whether  it  helps 
the  growth  of  the  fig  merely  by  pricking  it  in  order 
to  lay  its  eggs,  seems  to  be  a  doubtful  matter.  But 
some  growers  consider  that  the  insertion  of  an  oiled 
straw  answers  the  purpose  equally  well,  and  that, 
if  left  entirely  to  themselves,  the  figs  often  do  not 
develop. 

In  England,  however,  where  excellent  figs  ripen, 
especially  on  the  south  coast,  there  are  certainly  neither 
wild  figs,  nor  the  insects  frequenting  them,  to  give  any 
assistance ;  nor  are  any  artificial  means  resorted  to. 
But  whether  the  '  nuts '  contain  any  germ  or  not  is 
another  question. 


Seed-Scattering  249 

Whether  they  receive  assistance  or  not,  however, 
most  of  the  fig's  blossoms  produce  no  '  nuts,'  and  hence 
the  growth  of  the  sweet  flesh  must  be  in  some  degree, 
if  not  altogether,  independent  of  them. 

With  many  fruits,  as  already  said,  it  is  possible  to 
almost  or  entirely  do  away  with  the  seed,  and  still  to 
secure,  and  increase  the  size  of,  its  eatable  part.  This 
the  gardener  can  afford  to  do ;  but  nature  cannot,  for, 
without  seed,  no  offspring. 

Such  is  the  general  law,  the  exceptions  to  which 
have  been  already  referred  to.  But,  even  when  the 
plant  is  left  in  a  state  of  nature,  and  allowed  to 
produce  seed  in  abundance,  it  often  needs  further  help, 
if  its  progeny  are  to  grow  up  healthy,  and  vigorous 
enough  to  hold  their  own  among  their  many  com- 
petitors. The  seed  must  be  scattered. 

The  gardener  often  finds  it  advisable  to  get  his  seed 
from  some  little  distance,  the  plants  raised  from  it 
being  distinctly  better  than  those  grown  from  seed 
ripened  in  the  same  place.  This  is  one  reason  why  it 
is  for  the  plant's  good  that  its  seed  should  be  scattered ; 
and  here,  of  course,  we  mean  by  the  '  plant/  the  race, 
and  not  the  individual.  But  there  are  many  other 
reasons. 

If  seeds  are  dropped  close  round  the  parent-plant, 
in  a  confined  space,  they  grow  up  in  a  crowd,  and 
there  is  a  desperate  struggle  for  existence.  Being  all 
of  the  same  species,  they  all  want  the  same  kinds  of 
food,  and  none  have  much  advantage  over  the  rest. 
A  few  seeds  may  have  been  a  trifle  larger,  and  may 
produce  seedlings  a  trifle  stronger,  and  better  able  to 
battle  for  what  they  want ;  but  the  difference  is  usually 
slight,  and  the  chances  are  that  all  will  grow  up  weakly. 


2  50  Seed-  Scattering 

Where  seedlings  are  crowded  together  there  must 
always  be  a  struggle  as  to  which  shall  survive,  but  it  is 
much  more  severe  where  all  are  of  the  same  sort. 
Where  they  are  mixed,  some  will  have  advantages. 
They  may  be  larger  and  stronger,  or  they  may  be 
better  fitted  for  the  soil  and  situation.  Whatever  the 
advantage  may  be,  those  possessing  it  will  speedily 
overpower  their  less  fortunate  rivals,  and  then,  having 
secured  sufficient  elbow-room,  will  grow  up  strong  and 
healthy. 

Plants  of  different  species,  when  crowded  together, 
are  better  off  in  another  respect,  for  they  do  not  all 
want  precisely  the  same  amount  of  the  various  mineral 
foods,  and  so  there  is  more  for  all.  For  this  reason  it 
is  a  very  usual  thing  to  sow  a  grass-field  with  seed  of 
different  species ;  and  the  greater  .  the  variety,  the 
heavier  the  crop  of  hay,  because  the  plants  have  had 
a  better  opportunity  of  obtaining  food. 

On  this  account,  therefore,  as  well  as  that  they  may 
have  change  of  air,  it  is  well  for  seeds  that  they  should 
be  scattered,  or  otherwise  dispersed.  But  there  are 
other  reasons  still. 

Some  plants  need  shelter,  and  are  killed  by  sudden 
exposure.  If  they  had  no  means  of  dispersing  their 
seeds,  not  only  they,  the  parents,  but  their  whole 
progeny,  might  be  exterminated  by  the  removal  of 
trees,  etc.  Or  again,  by  the  draining  of  a  pond  or 
drying  up  of  a  brook,  plants  needing  much  moisture 
might  be  killed  out  of  a  neighbourhood,  if  all  their 
seeds  dropped  close  round  them,  while  they  might 
continue  to  flourish  if  they  were  able  to  migrate  the 
distance  of  only  a  few  yards. 

In  some  cases,  too,  the  parent  so  exhausts  the  soil, 


Seed-Scattering  251 

that  the  children  have  no  chance  of  thriving,  if  they 
grow  under  its  shadow ;  and  then  again,  if  cross-, 
fer/  ilization  be  an  advantage  to  the  plant,  even  where 
not  absolutely  essential,  it  certainly  seems — from  ex- 
periments made  in  crossing  Indian  corn  and  beans 
with  plants  grown  some  miles  away  —  that  cross- 
fertilization  with  plants  at  a  distance  is  more  beneficial 
still,  the  produce  being  in  each  case  very  greatly 
augmented. 

Such,  then,  are  the  strong  arguments  in  favour  of 
Nature's  plan  of  scattering  her  seed  far  and  wide :  the 
plants  gain  change  of  air  and  change  of  soil;  com- 
petition is  less  keen,  cross-fertilization  is  promoted; 
and,  when  driven  by  stress  of  circumstances  from  one 
neighbourhood,  they  are  able  to  gain  a  settlement  in 
another. 

By  one  means  and  another  seeds  are  widely  scattered, 
and  there  is  not  a  bare  patch  of  soil  on  railway- 
embankment  or  mountain-side  which  is  not  speedily 
sown. 

At  first  sight  it  would  seem  that  as  plants  are  rooted 
to  the  soil,  migration  would  be  impossible  as  well  for 
their  offspring  as  for  themselves ;  whereas,  in  reality, 
they  are  more  migratory,  and  wander  further  afield 
than  most  animals,  though  these  are  free  to  come  and 
go  as  they  will. 

Winds,  waves,  birds,  beasts,  fishes,  and  even  man 
himself,  are  all  pressed  into  the  plant's  service,  and 
made  to  act  as  seed-carriers.  But  in  some  cases  the 
plant  itself  acts,  and  acts  alone,  sending  her  seeds  to 
quite  considerable  distances. 

Many  years  ago,  there  was  a  certain  bare,  rocky 
crag  near  Dunkeld,  which  the  Duke  of  Athole  desired 


252  Seed-Scattering 

to  have  planted  with  trees,  though  he  was  quite  at  a 
loss  how  to  accomplish  it.  For,  as  the  place  was 
simply  inaccessible,  no  one  could  climb  up,  either  to 
sow  seeds  or  to  plant  saplings.  The  Duke  mentioned 
his  difficulty  to  Nasmyth,  and  he,  noticing  a  pair  of 
small  cannon  in  front  of  the  castle,  ordered  a  number 
of  tin  canisters,  filled  them  with  suitable  seeds,  and 
fired  them  from  the  guns  up  the  high  face  of  the  crag, 
where  they  burst,  and  scattered  their  contents  in  all 
directions.  Some  few  years  later  there  were  trees 
flourishing  luxuriantly  in  all  the  recesses  of  the  cliff. 

Plants  cannot  perhaps  shoot  their  seeds  quite  so 
effectually  as  this,  but  in  many  the  seed-vessels  split 
with  so  much  of  an  explosion  that  the  seeds  are  dis- 
charged to  distances  which,  at  all  events,  remove  them 
from  the  danger  of  being  squeezed  to  death  in  a  crowd. 
The  Touch-me-not  balsam  is  one  of  these.  But  the 
Sand-box  tree  of  Barbadoes  is  much  more  energetic. 
Its  fruit  is  rather  like  a  small  melon  in  shape,  but  hard 
and  woody,  and  when  ripe  it  bursts  with  a  loud  report. 
One  of  these — dried  very  gradually  in  the  hope  of  its 
remaining  intact — exploded  nine  months  after  it  was 
gathered,  and  so  violently  as  to  break  the  wooden  box 
in  which  it  was  kept  quite  to  pieces.  The  seeds  were 
scattered  in  all  directions,  but  would  of  course  have 
been  carried  very  much  further  had  they  been  uncon- 
fined. 

The  fruit  of  the  squirting  cucumber  has  to  be 
bound  round  with  copper-wire  when  ripe,  to  prevent 
its  shooting  out  its  seeds. 

The  pods  of  the  Chinese  wistaria  also  explode  with 
a  sharp,  loud  report,  and  the  seeds  may  be  carried  at 
least  thirty  feet;  while  those  of  the  American  wych- 


Seed-Scattering  253 

hazel  are  shot  out  to  a  distance  of  from  twenty  to 
five-and-forty  feet. 

If,  when  these  and  other  similar  seeds  are  discharged, 
a  strong  wind  should  happen  to  be  blowing,  they  may 
of  course  be  carried  much  further ;  and  even  if  it  be 
not  to  any  really  great  distance,  yet  it  will  give  them 
an  advantage  ;  their  descendants  will  advance  further 
still,  and  thus,  in  the  course  of  generations,  the  plants 
may  spread  over  very  wide  areas. 

Even  individual  seeds  transported  by  the  wind  do 
not  always  accomplish  the  whole  of  their  journey  '  all 
in  a  breath ' ;  for  the  wind  comes  in  successive  waves, 
not  in  one  continuous  blast. 

Of  a  hundred  seeds  carried  off  by  the  wind,  all  will 
be  dropped  when  the  first  lull  comes,  and  when  the 
next  gust  or  wave  rises,  probably  not  more  than  half 
will  be  lifted  up  again  to  continue  their  journey;  at  the 
third  wave,  perhaps  ten  will  be  caught  up  again,  but 
at  the  fourth  or  fifth,  probably  not  a  single  one,  for 
they  will  have  been  dropped  upon  damp  earth,  or 
water,  into  cracks,  under  bushes,  or  upon  moss,  all  of 
which  act  as  traps,  and,  once  caught,  do  not  readily 
give  them  up  again,  even  to  the  most  violent 
blast. 

Of  course,  the  lighter  the  seeds,  the  better  chance 
they  have  of  being  carried  far,  unless  they  are  caught 
in  these  ways ;  and  some  few  seeds,  such  as  those  of 
the  orchids,  are  so  exceedingly  minute  and  light,  that 
no  mere  lull  in  the  wind  is  enough  to  make  them  drop, 
for  they  manage  to  float  even  in  the  still,  draughtless 
air  of  a  hot-house.  In  this  respect  they  resemble  the 
spores  of  ferns,  mosses  and  fungi,  which  can  hardly 
come  to  the  ground  at  all  except  when  the  air  is 


234  Seed-Scattering 

almost  absolutely  motionless,  so  extremely  light  are 
they,  being,  in  fact,  rather  like  pollen  than  seeds. 

Spores,  owing  to  this  extreme  lightness,  travel 
immense  distances  over  sea  and  land,  and  are  to  be 
found  in  almost  all  dust,  whether  of  town  or  country ; 
but  in  damp  weather  they  are  not  carried  so  far,  and 
some  of  the  mosses  keep  the  capsules  in  which  their 
spores  are  contained  tightly  closed,  except  when  the 
air  is  dry  enough  to  ensure  them  a  long  journey. 

Seeds,  even  the  smallest,  with  very  few  exceptions, 
fall  straight  to  the  ground  when  the  air  is  still.  Even 
the  tiny  seeds  of  the  poppy,  campanula,  and  others  do 
this ;  but  then,  on  the  other  hand,  small  as  their 
weight  is,  they  require  something  of  a  shake  to  dis- 
lodge them  at  all,  and  as  they  get  this  only  when  there 
is  a  tolerably  strong  puff  of  wind,  they  must  needs  be 
carried  some  little  distance. 

It  might  seem  that  large,  heavy  seeds  would  be  at  a 
disadvantage  in  respect  of  wind  transport;  but  as 
they  need  a  stronger  shake  to  detach  them,  they  do 
not  begin  their  journey  till  the  wind  is  blowing  with 
some  little  force ;  and  then  again,  being  generally 
borne  by  trees,  and  tall  trees  too,  they  start  at  a 
favourable  height,  and  are  often  carried  a  long  way. 

Seeds  have,  indeed,  been  raised  as  much  as  5,400 
feet  in  the  air  by  the  wind  ;  but  hurricanes  are  usually 
local,  and  do  not  convey  what  they  snatch  up  more 
than  a  few  miles  at  the  utmost. 

But  we  have  been  looking  upon  seeds  hitherto  as  if 
they  were  themselves  perfectly  helpless  and  inactive, 
which  is  very  far  indeed  from  beirig  the  fact.  Many 
of  them  have  special  means  of  their  own  for  ensuring 
or  helping  their  conveyance  from  place  to  place  — 


Seed-  Scattering  255 

means  which  vary  according    to  the  carriers  upon 
which  they  depend  for  locomotion. 

Those  which  are  carried  by  the  wind,  for  example, 
have  elastic  spines,  wings,  feathery  tails,  down,  hairs, 
all  of  which  help  to  speed  them  on  their  way,  and 
make  it  more  easy  for  them  to  be  raised  in  the  air,  or 
blown  along  the  ground. 

Generally  as  the  lower  part  of  the  pistil  ripens,  the 
upper  part  withers,  having  done  its  work  of  conveying 
pollen  to  the  ovules.  But  sometimes  the  pistil-stalk 
remains  attached  to  the  ovary,  and  is  turned  to  a  fresh 
use.  In  the  wild  clematis,  for  instance,  so  far  from 
withering  it  grows,  and  not  only  lengthens  out  but 
becomes  silky  and  feathery,  ready  to  catch  any  puff  of 
wind,  and  very  easily  carried  through  the  air.  When 
it  drops,  the  heavier  end,  the  ovary  with  its  seed, 
naturally  touches  the  ground  first,  and  is  caught  at 
last,  perhaps  after  two  or  three  journeys,  in  damp  soil 
or  moss,  or  some  crack  in  the  earth. 

In  the  dandelion,  it  is  the  upper  part  of  the  calyx 
which  enables  the  seed  to  float  through  the  air.  A 
dandelion  blossom  is  composed  of  many  small  florets, 
each  having  its  own  calyx  and  pistil.  The  lower  part 
of  each  pistil  is  entirely  enclosed  in  its  own  small 
calyx,  and  inseparably  united  with  it.  The  upper  part 
of  this  calyx  is  divided  into  fine  feathery  hairs,  which 
at  first  form  a  crown  to  the  ovary,  and  look  as  if  they 
grew  from  it.  But  later,  as  the  ovary  ripens,  this 
crown  is  pushed  upwards  on  a  fine  stalk,  and  looks 
like  a  miniature  parachute,  or  an  umbrella  turned 
inside  out,  and  it  catches  the  wind  as  easily,  the  merest 
breath  being  enough  to  float  it. 

We  need  not  do  more  than  mention  the  down  of  the 


256  Seed-Scattering 

thistle  and  many  other  plants,  the  wing-like  appendages 
of  the  seeds  of  the  ash,  maple,  and  sycamore,  com- 
monly called  'keys,'  and  the  long,  paper-like  leaf-scales 
attached  to  the  flower-stalks  of  the  lime,  which  answer 
a  similar  purpose ;  or  the  wing-like  expansions  by 
which  many  seeds  are  themselves  bordered,  and  which 
act  the  part  of  miniature  sails. 

The  seeds  of  the  water-pink  of  Ceylon  are  helped  on 
their  way  by  other  means;  they  are  enclosed  in  circular 
heads,  measuring  eight  or  nine  inches  across,  and 
beset  with  elastic  spines  which  stand  out  in  all  direc- 
tions. These  heads  are  detached  from  the  stalks 
when  ripe,  and  are  whirled  over  the  sands  for  miles, 
bounding  along  on  the  spines,  and  dropping  their  seeds 
by  the  way.  Often,  of  course,  they  are  whirled  into 
the  water,  and  there  they  float,  the  upper  spines 
catching  the  wind,  and  acting  as  sails. 

Water,  indeed,  plays  a  most  important  part  in  the 
dispersal  of  seeds,  many  of  which,  if  carried  only  a 
short  distance  by  the  wind  to  begin  with,  may  con- 
tinue their  journey  and  travel  much  further  if  dropped 
into  river  or  sea,  especially  if  they  happen  to  reach 
one  of  the  many  ocean-currents. 

There  are  not  many  seed-bearing  plants  which  grow 
actually  in  the  water ;  but  one  of  these,  the  arrow- 
head, has  seeds  which  keep  afloat  a  long  time,  not 
because  they  are  so  remarkably  light,  but  because  they 
are  so  highly  polished  as  to  look  and  behave  as  if  they 
had  been  oiled.  They  do  not  even  become  wet,  for 
water  runs  off  them  ;  and  it  is  not  until  this  polish  has 
been  destroyed  by  much  rubbing  and  long  soaking  that 
they  can  be  got  to  sink. 

The  seeds  of  the  water-lilies,  white  and  yellow,  are 


Seed-  Scattering  257 

kept  afloat  for  some  time  by  means  of  air-bubbles. 
Large  fruits  often  float  longer  than  small  ones,  and 
could  hardly  be  transported  by  any  other  means  than 
water. 

Then,  however,  comes  the  all-important  question, 
how  far  the  seeds  are  affected  by  remaining  for  some 
time  in  water ;  and  here  again  they  vary  considerably, 
some  being  far  more  hardy  than  others. 

The  coco-nut,  for  instance,  being  enclosed  in  a  mass 
of  fibre,  floats  well,  and  is  able  to  stand  immersion  in 
either  fresh  or  salt  water  for  an  unusually  long  time, 
without  losing  the  power  of  germinating ;  and  coco- 
palms,  self-planted,  are  the  first  trees  to  spring  up 
upon  any  newly  exposed  coral-reef,  the  nuts  having 
been  floated  thither  from  some  more  or  less  distant 
coast.  When  making  experiments  to  ascertain  how 
long  seeds  might  remain  in  salt-water  without  being 
killed,  Mr.  Darwin  was  delighted  to  find  that  some 
grew  after  twenty-one  days'  immersion.  Many  ocean- 
currents,  as  he  reckoned,  travel  at  the  rate  of  a  mile 
an  hour,  so  that  these  seeds  might  be  floated  five 
hundred  miles  without  being  any  the  worse.  But, 
alas  !  he  had  overlooked  one  thing.  The  seeds  had 
been  under  water  all  this  time ;  and  as  Dr.  Hooker 
reminded  him,  '  If  they  sink,  they  won't  float  /'  Seeds 
vary  much  as  to  the  length  of  time  they  are  able  to 
remain  afloat,  and  these  seeds  could  not  have  been 
transported  at  all  by  water,  except  under  different 
circumstances,  such  as  while  they  were  still  enclosed 
in  their  seed-vessels,  or  even  attached  to  the  plant  or 
branch  on  which  they  grew. 

Some  few  seeds  grew  after  being  kept  for  137  days 
in  sea-water ;  so  that,  if  able  to  float,  they  might  have 


258  Seed-Scattering 

germinated  after  a  voyage  of  more  than  3,000  miles — 
a  distance  greater  than  that  which  lies  between  Europe 
and  America. 

The  question  was,  then,  whether  there  were  any  way 
in  which  they  might  float ;  and  it  was  found  that 
though  ripe,  freshly  gathered  hazel-nuts  sank  directly 
they  were  put  in  water,  they  would  float  for  as  much 
as  ninety  days,  and  then  germinate,  if  they  were  first 
dried. 

Now,  in  the  natural  state,  seeds  may  often  be  dried 
by  exposure  to  sun  and  air  before  they  are  washed,  or 
blown,  into  the  water ;  and  they  would,  some  of  them 
at  all  events,  be  then  perfectly  well  able  to  float.  A 
plant  of  asparagus,  for  example,  floated  nearly  as  long 
as  the  nuts,  after  being  dried,  and  its  berries  germi- 
nated ;  and  asparagus,  being  a  plant  which  grows  wild 
on  the  sea-coast,  would  have  especially  good  opportu- 
nities, therefore,  of  migrating. 

Drying  does  not  answer  the  purpose  with  all  plants, 
however ;  but  out  of  ninety-four,  upon  which  the  expe- 
riment was  tried,  eighteen  floated  more  than  twenty- 
eight  days,  and  some  much  longer,  quite  long  enough, 
in  fact,  to  allow  of  their  being  carried  from  one  con- 
tinent to  another. 

For  Mr.  Darwin's  estimate  of  a  mile  an  hour  as  the 
rate  at  which  ocean-currents  travel,  was  a  purposely 
low  one  ;  several  of  the  Atlantic  currents  travel  thirty- 
three  miles  a  day,  and  some  as  much  as  sixty  miles  a 
day,  so  that  any  of  these  eighteen  plants  might  have 
been  carried  some  hundreds  of  miles,  and  others  from 
three  to  five  thousand,  without  their  seeds  being  any 
the  worse  for  the  voyage. 

Some  seeds  appear  to  have  no  means  at  all  of  getting 


Seed-  Scattering  259 

themselves  transported  from  place  to  place;  but  it  will 
generally  be  found  that  these  are  seeds  which  have 
been  altered  by  cultivation.  The  grain  of  wheat 
and  rye,  for  instance,  falls  quite  naked  from  the  ear 
as  soon  as  it  is  ripe,  and  sinks  at  once  in  water;  and 
this  is  one  reason  why  neither  is  ever  found  wild.  Rice 
is  a  little  better  off,  for  each  grain  is  enclosed  in  a 
rough,  hard  case,  which  effectually  preserves  it  from 
injury,  and  probably  in  its  natural  state  it  was  able 
to  float  on  water.  But  now  that  its  size  and  weight 
have  been  increased  by  cultivation,  it  sinks  like  the 
others. 

Many  bean-like  and  pea-like  seeds  stand  immer- 
sion extremely  well,  and  some  of  these,  conveyed 
3,000  miles  or  so  by  the  Gulf  Stream  and  cast  upon 
the  Azores  and  on  the  Orkney  islands,  have  been  suc- 
cessfully grown  at  Kew  Gardens,  though  they  could 
not  establish  themselves  in  either  group  of  islands 
owing  to  the  unsuitable  climate  of  both. 

Among  the  islands  which  have  been  especially  in- 
debted to  ocean-currents  for  their  vegetation,  may  be 
mentioned  the  Bermudas,  more  than  half  of  whose 
flowering  plants  are  supposed  to  be  colonists.  The 
greater  number  of  these  belong  to  the  tropics  and 
West  Indies,  and  have  been  to  a  large  extent  brought 
by  the  Gulf  Stream,  which  is  constantly  throwing  up 
various  objects  on  the  shore — the  seeds  of  trees  among 
the  rest.  The  soapberry-tree,  for  instance,  has  been 
observed  to  spring  up  in  this  way,  from  seeds  thus  cast 
ashore. 

Seeds  may  occasionally  chance  to  be  conveyed 
across  the  ocean  in  drift-wood,  without  ever  coming 
in  contact  with  the  water  at  all ;  for  stones  and  small 


260  Seed-Scattering 

quantities  of  earth  are  sometimes  found  perfectly 
enclosed  ;  and  from  the  earth  thus  entangled  in  the 
roots  of  an  oak,  Mr.  Darwin  was  able  to  grow  three 
plants. 

But  again,  there  is  another  way  in  which  seeds  may 
escape  contact  with  water:  dead  birds,  having  seeds 
in  their  crops,  may  now  and  then  escape  being  devoured, 
and  may  be  floated  long  distances  by  river  or  ocean- 
currents  ;  and,  as  many  seeds  retain  their  vitality  after 
being  in  a  bird's  crop  for  thirty  days,  some  may  be 
conveyed  in  this  way  from  time  to  time. 

The  so-called  'goose-wheat'  of  Canada  was  first 
sown  from  grain  found  in  the  crop  of  a  wild  goose 
which  was  shot  on  its  way,  probably  from  Alaska,  or 
the  Russian  settlements  on  the  other  side  of  Behring's 
Straits.  Migratory  geese  invariably  take  to  the  stubbles 
when  on  their  way  to  the  south  in  autumn,  and  many 
or  most  of  them  would  probably  be  found  to  have  grain 
in  their  crops,  though  the  chances  of  its  getting  planted 
are  small.  In  this  case,  however,  the  *  wild-goose 
barley,'  as  it  is  also  called,  has  become  a  permanent 
colonist,  and  is  still  grown  in  Saskatchewan. 


XVIII. 

SEED-CARRIERS 

THE  seed-carriers  now  to  be  considered  are  employed 
for  the  most  part  with  as  little  reference  to  their  own 
wills,  and  often  with  as  little  knowledge  on  their  parts, 
as  the  winds  and  waves.  The  seeds  simply  make  use 
of  them  as  carriers,  whether  they  will  or  no,  and  that 
no  matter  whether  they  be  birds,  animals,  or  even 
men ;  for  all  are  pressed  into  the  service,  and  know, 
for  the  most  part,  nothing  of  what  they  are  doing. 
We  are,  of  course,  not  here  speaking  of  man's  voluntary 
importations,  but  of  his  involuntary  ones,  which  are 
probably  almost  as  many. 

There  are,  however,  some  few  voluntary  carriers 
among  both  birds  and  animals — carriers  who,  though 
in  one  sense  quite  unaware  of  what  they  are  doing,  yet 
for  purposes  of  their  own  do  carry  seeds  from  one  place 
to  another,  not  very  far  probably,  but  often  the  distance 
of  a  few  miles. 

Some  birds,  for  instance,  take  a  positive  pleasure,  as 
it  would  seem,  in  carrying  things  about  for  the  mere 
sake  of  carrying  them  ;  and  the  propensity  is  especially 
strong  in  the  crow  tribe,  including  not  only  crows,  but 
rook,,  jays,  magpies  and  jackdaws,  many  of  which 
also  have  a  great  love  of  hiding  as  well  as  carrying. 


262  Seed-Carriers 

Rooks  seem  to  be  especially  busy  in  this  way,  at  all 
events  in  America,  where  they  are  said  to  be  per- 
petually carrying  things  about  in  their  claws,  with 
which  they  are  able  to  grasp  even  hens'  eggs. 

On  one  occasion  a  large  number  of  fowls,  destined 
for  New  Orleans,  had  been  collected  at  some  spot  up 
the  river,  and  as  the  boat  which  was  to  convey  them 
was  not  ready,  they  were  turned  out  into  the  woods 
for  about  a  week  to  shift  for  themselves.  During  this 
time  they  laid  about  two  thousand  eggs  daily,  a  fact 
which  seemed  immensely  to  interest  the  rooks  of  the 
neighbourhood.  For,  whether  with  a  view  to  eating 
them,  or  simply  from  a  love  of  being  busy,  they  devoted 
themselves  to  carrying  the  eggs  away,  and  burying 
them  in  a  field  more  than  half  a  mile  off  on  the  other 
side  of  a  creek.  A  month  or  two  later,  when  the  field 
was  ploughed,  the  eggs  were  turned  up  in  hundreds, 
and  being  still  perfectly  good,  supplied  the  labourers 
with  many  a  meal. 

But  now,  supposing  that  the  rooks  had  buried  acorns 
instead  of  eggs,  and  that  the  field  had  been  waste 
ground,  where  plough  and  harrow  never  came,  might 
not  a  small  forest  of  oaks  have  sprung  up  ?  and  may 
not  many  a  plantation  of  oaks,  beeches,  sycamores  and 
other  trees,  have  been  planted  in  a  similar  way  ? 

A  certain  pine-forest  in  Minnesota,  for  example,  on 
being  cut  down,  was  at  once  succeeded  by  oaks ;  and 
a  similar  thing  is  said  to  have  occurred  in  North 
Carolina,  with  nothing  in  either  case  to  account  for  it. 
The  oaks  seemed  to  have  grown  of  themselves;  but 
since  oaks  must  certainly  spring  from  acorns,  it  seems 
at  least  possible,  and  indeed  probable,  that  rooks  may 
have  been  the  planters. 


Seed-Carriers  263 

Rooks  are  always  busy  in  the  wild  state,  and,  as  the 
American  writer  before  quoted  remarks,  on  leaving  an 
oak-tree,  the  bird  will  often  pluck  an  acorn,  which  it 
may  carry  perhaps  five  miles ;  then,  if  it  alights  upon 
a  beech,  it  will  drop  the  acorn  and  gather  nuts  instead, 
and  so  on,  taking  a  fresh  remembrance  away  wherever 
it  goes,  and  sowing  seeds  innumerable  in  the  course  of 
its  life. 

But  when  the  rooks  assemble  in  their  hundreds  to 
hold  a  'pow-wow'  or  parliament,  then  is  the  time 
when  they  do  their  sowing  on  a  large  scale ;  for,  true 
to  their  usual  habits,  many,  if  not  all,  bring  and  drop 
something.  The  place  chosen  for  the  assembly  is 
always  open,  and  more  or  less  bare,  and  afterwards 
the  ground  may  be  seen  strewn  with  walnuts,  hickory 
nuts,  acorns,  sticks  and  other  rubbish.  This,  at  least, 
is  how  rooks  behave  in  America ;  and  a  field  is 
mentioned  which,  after  being  left  to  itself  for  some 
time,  was  found  to  be  full  of  young  '  bur-oaks,'  there 
being  no  parent-tree  anywhere  near  from  which  the 
acorns  could  possibly  have  been  carried,  even  by  a 
high  wind. 

Now,  how  could  these  have  been  planted,  save  by 
birds  ?  Pigs  simply  crunch  up  and  eat  nuts  and  acorns 
where  they  find  them ;  and  though  the  squirrel  some- 
times carries  them  several  hundred  yards,  it  seldom 
does  more,  while  the  field-mouse  certainly  does  not 
lay  up  her  winter-store  very  far  from  where  her  crops 
grow.  Besides,  neither  tree-squirrels  nor  mice  act  in 
concert,  and  planting  on  so  large  a  scale  must  have 
required  a  small  army  to  accomplish  it. 

No  doubt,  however,  both  tree-  and  ground-squirrels, 
as  well  as  mice,  are  responsible  for  the  planting  of 


264  Seed-Carriers 

many  a  single  nut -bearing  tree;  for  sometimes  they 
may  be  startled,  and  made  to  drop  their  treasure 
before  they  reach  home ;  some  may  forget  their  store- 
house, and  some  may  die  before  it  is  empty.  Still, 
the  result  of  any  of  these  accidents  will  be  rather 
solitary  trees  than  groves,  or  even  groups ;  for  in  the 
case  of  an  abandoned  store-house,  though  many  might 
sprout,  only  one  or  two  would  have  a  chance  of 
growing. 

But  the  gray  tree-squirrels  may  have  done  more, 
for,  unlike  the  red,  and  the  ground-squirrels,  they  bury 
their  winter-store  of  nuts  and  acorns  separately,  one  by 
one,  about  a  couple  of  inches  deep ;  and  though  they 
have  such  good  memories  as  to  be  able  to  find  them 
again,  even  when  buried  under  a  foot  of  snow,  no 
doubt  in  many  cases  accidents  have  happened,  and 
their  stores  have  been  left  undisturbed,  and  would 
have  excellent  opportunities  of  growing.  The  number 
of  these  little  animals  in  North  America  was  some- 
thing extraordinary  in  bygone  times ;  for  in  one  year 
(1749)  640,000  were  destroyed  in  Pennsylvania  alone. 
They  may  well,  therefore,  have  done  a  great  deal  of 
planting,  though  they  would  probably  not  carry  their 
nuts  far. 

The  nuthatch  often  plants  quite  a  colony  of  young 
beeches  around  its  haunts;  for  it  has  favourite  trees 
to  which  it  resorts,  after  twisting  a  cluster  of  nuts  from 
the  bough ;  its  object  being  to  fix  the  nuts  in  some 
crevice  of  the  bark  where  it  may  hammer  at  them. 
Very  often,  however,  it  fails  in  the  attempt,  the  nuts 
fall  to  the  ground,  and,  under  favourable  circumstances, 
germinate. 

Monkeys,  also,  sometimes  carry  nuts  and  fruits  to  a 


Seed-Carriers  265 

distance  before  eating  them ;  and  if  meantime  their 
attention  be  caught  by  something  else,  they  will  prob- 
ably drop  and  forget  all  about  them.  Brazil-nuts, 
for  instance,  are  enclosed  in  such  a  very  hard,  strong 
outer  case  that  no  monkey  can  get  at  the  contents, 
except  by  hammering  it  for  a  long  time  against  a  rock, 
or  a  hard  log  of  wood,  neither  of  which  is  always  to 
be  found  close  at  hand. 

So  much,  then,  for  the  voluntary  carriers,  whose 
work  is  but  small  and  limited,  compared  with  that 
of  the  great  army  of  involuntary  carriers. 

Look,  for  example,  at  a  dog  when  he  has  been 
hunting  in  a  ditch,  and  see  how  the  burdocks  and 
goose-grass,  or  cleavers,  have  taken  advantage  of  him, 
and  made  him  act  as  carrier  for  them.  Their  fruits 
are  thickly  set  with  tiny  hooks,  and  with  these  they 
have  laid  hold  of  his  coat,  entangling  themselves  in  it, 
and  holding  so  tight,  that  though  he  may  roll  and 
bite,  and  try  in  every  way  to  rid  himself  of  them, 
he  will  often  carry  some  about  with  him  for  days ; 
and  if  on  some  long  expedition,  might  travel  a  good 
many  miles  before  he  had  freed  himself  from  them 
all.  ' 

Now,  what  is  true  of  the  dog  in  this  respect  is  true 
also  of  many  animals,  wild  and  domestic,  including  man 
himself.  The  fleece  of  sheep,  the  fur  and  hair  of  other 
animals,  the  feathers  of  birds,  the  clothes  of  human 
beings — all  answer  the  purpose  of  these  hooked,  barbed 
and  thorny  fruits,  by  giving  them  something  which 
they  can  lay  hold  of.  No  doubt  we  have  all  noticed 
the  extraordinary  way  in  which  the  seeds  of  the  wild 
barley  work  their  way  into  one's  garments,  and  remain 
for  months  unless  picked  out  The  seeds  of  the  porcu- 


266  Seed-  Carriers 

pine-grass,  too,  cause  positive  annoyance  by  a  similar 
habit  of  sticking  into  socks  and  trousers. 

This  is  the  way  in  which  seeds  of  these  sorts  get 
themselves  transported  ;  and  accordingly  it  will  be 
found  that  fruits  furnished  with  these  means  of  laying 
hold  of  the  passer-by  generally  grow  low  enough  down 
to  be  within  reach  of  some  one  or  other  of  these  means 
of  conveyance.  Hides,  fleeces,  hair,  wool,  fur,  feathers, 
manes,  tails — all  are  turned  to  account,  and  made 
useful. 

It  is  true  that  both  birds  and  quadrupeds  are 
frequently  cleaning  themselves,  and  do  not  willingly 
carry  anything  of  the  sort  about  with  them ;  but  when 
once  a  bur  has  attached  itself,  it  is  very  difficult  to  get 
rid  of  again  ;  and  the  animal  which  it  has  made  use 
of  will  generally  be  obliged  to  carry  it  for  a  time,  how- 
ever unwillingly. 

We  have  abundant  proof  of  this  in  the  way  in  which 
more  than  one  plant  has  been  introduced,  not  only 
from  one  continent,  but  from  one  hemisphere,  to 
another,  within  recent  times. 

The  '  Bathurst  bur,'  among  others,  is  a  striking 
example  of  the  successful  emigrant.  Growing  in 
Patagonia,  it  got  itself  conveyed  to  Australia,  where  it 
has  flourished  ever  since  in  the  most  rampant  manner. 
The  first  step  was  to  hook  its  burs  into  the  tails  and 
manes  of  horses,  which  it  did  most  effectually;  and 
then,  as  chance  would  have  it,  some  of  these  same 
horses  were  imported  into  Australia,  burs  and  all,  for 
>o  thoroughly  were  they  entangled  that  the  animals 
had  not  been  able  to  shake  or  rub  them  all  off,  even 
during  the  voyage.  Some  no  doubt  were  got  rid  of, 
but  enough  remained  to  make  a  fresh  start  in  the  new 


Seed- Carriers  267 

country  ;  and  they  did  it  with  such  energy,  that  within 
a  few  years  it  was  found  necessary  to  pass  an  Act  of 
Parliament  '  against  the  growth  of  thistles,'  and  all 
persons  allowing  them  to  remain  on  their  land,  or  even 
on  their  half  of  the  road,  were  made  liable  to  heavy 
fines. 

The  '  Bathurst  bur '  was  in  fact,  from  man's  point 
of  view,  a  terrible  nuisance ;  but  from  its  own,  it  was 
a  peculiarly  successful  colonist.  It  had  secured  such  a 
change  of  air  and  change  of  soil  as  agreed  with  it 
amazingly;  it  had  made  use  first  of  the  horses,  then 
of  man,  to  attain  its  object ;  and  finally,  on  reaching 
the  new  continent,  its  downy  seeds,  being  fully  ripe, 
had  been  launched  on  the  winds,  and  borne  hither  and 
thither  to  their  new  settlements.  Their  descendants, 
again,  had  been  carried  yet  further  afield,  and  so  with 
giant  strides  it  had  advanced  over  the  country — a  most 
successful  plant ! 

The  merino  sheep  has  been  similarly  instrumental 
in  introducing  another  thistle-like  plant  to  South 
Africa.  Indeed,  plants  with  downy  seeds  have  been 
eminently  successful,  not  only  in  dispersing  their 
offspring  far  and  wide  but  also  in  becoming  natural- 
ized— making  themselves  so  thoroughly  at  home  in 
their  new  quarters  that  they  are  able  to  mature  their 
seed,  and  so  to  propagate  their  species  without 
artificial  help. 

But  birds  are  uie  great  carriers ;  and  the  migrants, 
especially,  transport  such  seeds  as  lay  hold  of  them  to 
much  greater  distances  than  quadrupeds  ever  travel, 
at  least  without  the  help  of  man. 

There  is  a  species  of  sedge  which  grows  by  the 
water  in  the  highlands  of  Jamaica,  whose  fruit  is 


268  Seed-Carriers 

provided  with  long  bristles,  something  like  a  shepherd's 
crook,  the  hooked  part  being  so  closely  fitting  and 
elastic  as  to  grasp  the  finest  hairs,  if  drawn  across  the 
back  of  the  hand.  It  grasps  them  so  tight,  moreover, 
as  to  pull  them  out,  sooner  than  let  go.  The  highlands 
where  this  sedge  abounds  are  the  spots  generally  first 
touched  by  migratory  birds,  and  in  some  cases  small 
birds  are  caught  and  held  so  firmly  by  the  sedge's 
hooks  as  to  be  quite  unable  to  escape.  Larger  and 
stronger  birds  of  course  get  away,  but  must  carry  many 
of  the  seeds  with  them ;  and  these,  as  the  bristles 
wither  and  relax  their  hold,  are  dropped  by  the  way. 
Accordingly  the  sedge  is  plentiful  all  along  the  track 
followed  by  these  birds  —  the  east  coast  of  North 
America,  that  is,  and  the  adjacent  islands,  among 
which  the  Bermudas  are  visited  by  large  numbers  of 
these  migrants. 

Birds,  such  as  the  puffins,  which  burrow  in  the 
earth,  get  their  feathers  covered  with  vegetable  mould, 
which  is  sure  to  contain  spores  and  seeds,  some  of 
which  may  cling  long  enough  to  be  carried  at  least 
part  of  the  way,  when  the  birds  leave  their  inland 
nesting  places  for  the  coast,  where  they  spend  the 
greater  part  of  the  year. 

Birds,  it  is  true,  are  generally  very  particular  in 
keeping  both  beak  and  feet  clean,  but  still  sometimes 
they  are  found  with  little  cakes  of  earth  adhering  to 
them ;  and  seeds  are  so  very  common  in  all  soil,  that 
some  no  doubt  are  transported  in  this  way.  Indeed, 
eighty-two  plants  have  been  grown  from  the  earth  taken 
from  the  leg  of  a  single  partridge,  and  that  after  the 
earth  had  been  kept  three  years.  This  partridge  had 
carried  as  much  as  six  and  a  half  ounces  of  earth  on 


Seed-Carriers  269 

its  leg ;  and  what  one  has  done,  others  of  course  may 
do,  and  probably  have  done.  Still,  dirt  on  feet  and 
beaks  is  rare. 

The  birds  most  likely  to  have  muddy  feet  are 
naturally  the  waders,  and  those  which  frequent  the 
edges  of  ponds  and  moist  and  muddy  places.  And 
these,  if  they  carry  away  mud,  are  certain  to  carry 
away  seeds  also,  for  damp  soil  catches  and  keeps  the 
seed  dropped  upon  it  in  a  way  that  dry  soil  cannot. 
From  about  a  breakfast  -  cupful  of  mud  taken  from 
under  the  water,  and  from  the  edge,  of  a  small  pond, 
Mr.  Darwin  succeeded  in  raising  537  plants. 

Now  the  birds  which  frequent  bogs  and  marshes  and 
other  muddy  places,  are  also  the  very  birds  which 
wander  most,  the  migrants,  in  fact,  chief  among  which, 
for  the  wide  extent  of  its  journeyings,  is  the  wood- 
cock ;  for  there  is  hardly  any  island,  however  remote, 
but  the  woodcock  finds  its  way  thither,  and  no  doubt 
it  has  carried  in  its  time  many  a  seed,  which  has  been 
dropped  again  in  soil  as  muddy  as  that  from  which  it 
was  taken,  and  has  therefore  had  a  good  chance  of 
establishing  itself. 

But,  though  birds  convey  seeds  both  in  their  feathers 
and  in  the  mud  on  their  feet,  they  no  doubt  convey 
many  more  in  their  crops.  There  is  no  gastric  juice 
or  anything  else  in  the  crop  to  injure  the  seeds  in  any 
way ;  and  when  a  large  supply  of  food  has  been  taken, 
the  grains  do  not  all  pass  into  the  gizzard  for  twelve, 
or  even  eighteen  hours,  in  the  course  of  which  time  a 
good  deal  might  happen.  Birds,  for  example,  are 
occasionally  blown  the  whole  way  across  the  Atlantic, 
the  wind  carrying  them  on  at  the  rate  of  thirty-five 
miles  an  hour ;  and  they  might  well,  therefore,  be 


270  Seed- Carriers 

carried  500  miles  before  all  the  grain  had  passed  out 
of  their  crop,  if  they  had  just  had  a  full  meal. 

Supposing  them  to  be  blown  overland,  instead  of 
over  sea,  or  to  reach  land  after  a  few  hours,  they  might 
then  be  pounced  on  by  the  hawks,  who  are  always  on 
the  look-out  for  weary  travellers.  These,  like  the  owls, 
bolt  their  prey  whole,  and  after  some  hours  disgorge 
pellets  of  feathers  and  other  undesirable  matter,  among 
which  might  be  the  seed  in  the  crop  of  their  victim, 
still  uninjured.  This,  indeed,  is  no  mere  speculation, 
for  it  has  been  found  by  experiment  that  such  pellets 
do  contain  seeds,  such  as  oats,  wheat,  hemp,  millet, 
clover,  and  canary-seeds ;  all  of  which  may  be  capable 
of  germination.  Or  again,  a  bird  with  seed  in  its  crop 
may  be  struck  down  by  a  hawk  after  flying  some 
considerable  distance,  and  the  hawk  in  its  turn  may 
be  driven  away  from  its  prey  before  it  has  done  more 
than  tear  the  crop  open.  In  this  instance,  too,  the 
seed  may  fall  where  it  will  be  able  to  germinate,  and 
the  plant  may  be  able  to  establish  itself;  and  though 
such  cases  are  exceptional,  one  single  successful  seed 
is  enough  to  introduce  a  plant  to  an  entirely  new 
neighbourhood,  where,  under  favourable  circumstances, 
it  may  spread  and  become  completely  naturalized. 

Seeds  vary  very  much  as  to  their  power  of  resisting 
digestion.  Many  are,  for  the  most  part,  quite  digested, 
but  there  are  others  which  are  protected  against 
digestion  by  a  covering  so  hard,  or  so  tough,  that  it  is 
a  real  help  to  them  to  be  swallowed,  as  they  germinate 
more  readily  when  this  covering  has  undergone  some 
amount  of  softening. 

Seeds,  for  instance,  which  are  swallowed,  not  for 
their  own  sake,  but  for  the  sweet  flesh  surrounding 


Seed-  Ca  rriers  271 

them,  are  more  or  less  hard,  and  some  stone-like. 
Even  the  seeds  of  elms,  firs  and  ashes,  often  escape 
not  merely  uninjured,  but  actually  helped  by  being 
swallowed ;  and  the  same  is  true,  in  a  much  more 
marked  degree,  of  the  stones  of  the  cherry,  sloe,  rasp- 
berry, blackberry,  and  the  seeds  of  the  apple,  and  the 
tiny  nuts  of  the  strawberry. 

In  some  cases  birds  render  a  positive  service  to  man, 
also,  by  swallowing  and  scattering  the  seeds  of  plants 
which  he  cultivates.  The  cinnamon-tree,  for  instance, 
has  been  introduced  in  this  way  into  the  interior  of 
Ceylon  from  the  gardens  on  the  coast ;  and  as  the  wild 
trees  are  just  as  good  as  the  cultivated  ones  for  com- 
mercial purposes,  their  shoots  are  regularly  cut  for  the 
trade. 

So,  too,  with  the  pimento,  allspice,  or  Jamaica 
pepper-tree.  All  the  present  '  pimento  walks '  of 
Jamaica,  as  the  plantations  are  called,  have  been  sown 
by  birds ;  for  though  the  plants  can  be  raised  in 
nurseries  in  large  numbers  by  careful  treatment,  the 
planters  are  of  opinion  that  the  seeds  are  better  pre- 
pared by  the  birds.  And  why  should  they  incur  the 
trouble  and  expense  of  this  '  careful  treatment/  when 
the  birds  do  all  that  is  necessary  ? 

When  a  new  '  walk '  is  wanted,  all  that  is  necessary 
is  to  enclose  a  piece  of  waste  ground  near  an  old 
'  walk.5  The  birds  eagerly  eat  the  fruit  when  ripe,  and 
the  seeds  are  dropped,  with  the  result  that  twelve 
months  after  the  first  rains  abundance  of  young  plants 
are  to  be  seen  growing  vigorously  in  all  parts  of  the 
new  enclosure.  If  not  enclosed,  the  plants  would  be 
eaten  off  or  trodden  down  by  wild  animals ;  but  this 
amount  of  protection  is  all  that  they  require. 


272  Seed-Carriers 

Turkeys  are  employed  to  prepare  the  haws  when 
hawthorn  hedges  are  wanted,  in  some  parts  of  France  ; 
for  the  bony  cores  are  quite  indigestible,  and  are 
softened  by  being  swallowed.  Blackbirds,  jays,  and 
others  keep  the  haws  in  their  crops  for  a  time,  and 
then  bring  up  the  seeds  clean  and  whole,  with  the  thin 
covering  of  flesh  gone  ;  and  no  doubt  they  are  respon- 
sible for  the  planting  of  many  a  thorn-tree. 

Some  trees  seem  to  be  entirely  dependent  upon 
birds  for  getting  their  seeds  scattered,  and  cannot 
spread  without  them.  The  red  cedar  is  apparently  one 
of  these;  for,  though  introduced  into  Indiana  nearly 
fifty  years  ago,  it  did  not  run  -wild,  and  was  not  to  be 
found  in  the  forest,  until  some  of  the  birds  became 
sufficiently  familiar  with  it  to  venture  to  eat  the  seeds. 
During  the  last  few  years  numbers  of  young  saplings 
have  made  their  appearance,  and  it  is  likely  to  be  one 
of  the  forest-trees  of  the  future.  The  seeds  of  the  red 
cedar  have  so  hard  an  outer  covering  that  gardeners 
find  it  well  to  scald  them  before  planting ;  and  it  is 
therefore,  no  doubt,  a  great  advantage  to  them  to  be 
swallowed. 

How,  except  by  being  swallowed  by  birds,  does  the 
mountain-ash  berry  get  conveyed  to  the  top  of  high 
walls,  where  young  trees  may  sometimes  be  seen 
growing?  How,  save  in  this  way,  does  the  mistletoe 
reach  the  top  of  the  oak  ?  or  how  do  the  wild-rose  and 
privet  find  their  way  to  the  walls  of  Cologne  Cathedral  ? 
The  reader  may  possibly  be  inclined  to  add  another 
'  how '  to  the  series,  and  ask  how,  when  they  get  there, 
do  they  manage  to  find  soil  to  germinate  and  grow  in  ? 
But,  as  already  remarked,  a  very  little  soil  is  enough 
for  seeds  to  sprout  in ;  and  this,  in  the  case  of  build- 


Seed-Carriers  273 

ings,  is  provided  first,  probably,  by  the  decay  of  lichens 
and  mosses  and  of  the  stone  itself,  and  also  by  the 
wind,  which  conveys  many  a  little  pile  of  dust  into 
sheltered  nooks  and  corners.  As  for  the  mistletoe, 
being  a  parasite  and  living  by  the  labour  of  others,  it 
has  no  difficulty  about  soil,  and  makes  itself  at  home 
not  only  on  the  oak,  but  on  other  trees,  above  all  on 
the  apple. 

In  the  forests  on  the  Amazons,  plants  without 
number  may  be  seen  growing  on  the  trees,  some  of 
which,  as  the  ferns  and  orchids,  have  no  doubt  been 
sown  by  the  wind ;  while  there  are  others,  such  as  the 
fragrant  pink-and-white  clusia,  which  are  equally  surely 
sown  by  the  birds.  The  large,  round,  whitish  fruit  of 
the  clusia,  called  the  '  wild  onion/  is  much  eaten  by 
birds,  and  is  to  be  seen  growing  on  almost  every  other 
tree. 

Tropical  birds,  whether  in  the  east  or  in  the  west, 
are  all  chiefly  fruit  or  insect  eaters ;  while  in  temperate 
latitudes,  where  there  is  much  grass,  seed-eaters  abound, 
and  a  mixed  diet  is  more  general. 

The  fruit-eating,  and  consequently  seed-carrying, 
birds  of  the  tropics  are  the  countless  multitudes  of  the 
parrot  tribe,  which  usually  feed  in  flocks  of  thousands, 
and  wander  far  in  search  of  food ;  and,  besides  these, 
there  are  many  fruit-eating  pigeons,  hornbills,  and 
others.  Nor  must  the  immense  flocks  of  large  fruit- 
bats,  or  flying  foxes,  be  overlooked ;  for  their  numbers 
are  so  enormous  that  they  often  take  hours  to  pass, 
while  their  depredations  in  the  orchards  are  carried  to 
such  an  extent  as  to  make  them  one  of  the  greatest 
pests  of  the  tropical  fruit-grower  of  the  East.  In  his 
absence,  however,  the  fruit-eaters  have  done,  and 

18 


2  74  Seed-  Carriers 

do,  much  valuable  service  in  the  way  of  carrying 
seeds. 

Seed  cannot  be  sown  to  any  purpose  until  it  is  ripe, 
and  it  would  therefore  be  simply  wasted  if  the  birds 
carried  it  off  too  soon.  But  it  is  safe  enough  from 
them  while  it  is  unripe,  for  the  eatable  part,  the  flesh 
surrounding  the  seed,  is  unripe  too,  as  the  birds  very 
well  know,  and  they  leave  it  severely  alone.  Green 
fruit  they  do  not  like,  probably  because  it  is  indiges- 
tible ;  for  one  would  not  suppose  the  flavour  to  be  of 
much  consequence. 

The  fruits  of  the  bird-cherry,  hawthorn,  ash,  sloe, 
and  many  others  are  of  a  size  to  be  swallowed  whole  ; 
and  as,  to  our  taste  at  all  events,  they  have  no  flavour 
to  recommend  them  even  when  ripe,  a  little  unripeness 
would  not  seem  to  matter  much,  except  as  regards  the 
seed.  But  for  this  it  would  matter  greatly,  and  the 
birds  are  therefore  warned  off  until  it  is  ready  to 
benefit  by  their  attention.  When  the  right  time  has 
come,  the  fruit  changes  colour  and  becomes  more  con- 
spicuous— a  notice  which  is  perfectly  understood. 

Red,  yellow,  purple,  and  black  are  the  most  usual 
colours  of  ripe  fruit,  and  these  the  birds  seem,  there- 
fore, to  understand  best ;  for  they  seldom  touch  white 
currants  till  the  red  are  gone,  though  the  white  are  the 
sweeter  of  the  two ;  and  they  have  been  observed  to 
leave  unnoticed  a  holly-tree  bearing  yellow  berries, 
while  they  stripped  other  trees  near  of  their  ordinary 
red  ones.  Yellow  holly-berries  being  uncommon,  these 
were  probably  considered  to  be  still  unfit  for  eating. 

Though  birds  swallow  their  own  small  fruits  whole, 
they  seem  to  appreciate  the  sweeter  flavour  of  those 
which  man  has  improved  by  cultivation.  But  as  seed- 


Seed-  Ca  rriers  275 

carriers  they  are  distinctly  out  of  place  both  in  orchard 
and  kitchen-garden  ;  they  are  not  wanted  in  that  capa- 
city, and,  in  fact,  if  they  were,  they  are  incompetent ; 
for,  where  cherries  and  plums  have  been  so  increased 
in  size  that  they  can  only  be  pecked  at,  not  swallowed, 
the  flesh  only  is  taken,  and  the  stones  are  left. 

Where  plants  are  cultivated  for  the  sake  of  their 
leaves  or  roots,  not  their  fruit,  the  former  are  altered, 
but  the  latter  remains  the  same,  with  the  same  means 
of  getting  its  seed  carried  to  a  distance  which  were 
possessed  by  the  plant's  wild  ancestors.  The  fruit  of 
the  garden  carrot,  for  instance,  like  that  of  the  wild,  is 
covered  with  minute  hooked  bristles  ;  that  of  the  par- 
snip is  winged  ;  and  the  seeds  of  the  onion,  tobacco, 
and  flax  are  just  as  easily  scattered  by  the  wind  in  the 
cultivated  as  in  the  wild  state. 

But  to  mention,  in  conclusion,  some  of  the  other 
seed-carriers  besides  the  birds.  Among  these  must 
be  reckoned  fish,  locusts,  cattle,  and,  perhaps  above 
all,  pigs. 

Fish  swallow  the  seeds  of  many  water  and  land 
plants,  including  even  the  large  seeds  of  the  water-lily; 
but,  being  confined  to  their  own  pond,  lake,  or  river, 
their  range  is  necessarily  limited.  When,  however, 
they,  in  their  turn,  are  swallowed  by  herons,  storks, 
kingfishers,  and  other  fish-eating  birds,  the  seeds  may 
be  conveyed  to  much  greater  distances  and  be  dropped 
quite  uninjured.  Some  large  seeds  of  the  great  southern 
water-lily,  for  instance,  found  in  the  stomach  of  a 
heron,  had  probably  first  been  swallowed  by  a  fish. 

The  locusts  which  frequent  parts  of  South  Africa 
are  believed  by  the  farmers  to  have  introduced  there 
various  new  plants  which  are  injurious  to  the  grass ; 


2  7  6  Seed-  Carriers 

and   it  is  a   fact   that  undigested   seeds,  capable  of 
germinating,  are  found  in  their  droppings. 

Cattle  and  pigs,  but  especially  the  latter,  are  respon- 
sible for  the  rampant  way  in  which  apple-trees  are 
now  running  wild  and  forming  extensive  groves  in  the 
Pampas.  The  pips  are  so  well  protected  as  to  be 
indigestible  even  by  a  pig;  and  the  same  may  be  said 
of  peach-stones,  which  have  also  been  extensively 
scattered  in  New  Zealand  and  elsewhere,  by  similar 
means  and  with  similar  results. 


XIX. 

CHANCES  OF  LIFE 

OF  all  the  wonderful  things  in  nature,  surely  a  seed  is 
one  of  the  most  wonderful.  How  dead  and  helpless 
it  looks ;  how  very  little  it  tells  us  about  itself,  and  yet 
how  very  much  is  wrapped  up  in  it !  Seeds,  especially 
small  seeds  from  the  same  plant,  look  just  as  much 
alike  as  grains  of  sand.  Indeed,  peas  have  become 
proverbial;  and  we  say  'as  much  alike  as  peas  in  a 
pod,'  when  we  mean  that  things,  or  people,  are  quite 
without  individual  character. 

And  yet  each  seed,  even  the  smallest  and  most  dust- 
like,  has  a  character  of  its  own — a  character  which 
distinguishes  it  not  merely  from  other  seeds  of  different 
families,  but  a  character  which  distinguishes  it  also 
from  all  its  nearest  relations,  even  from  those  which 
grew  in  the  same  pod  with  it. 

Probably  it  is  only  want  of  sight  which  prevents  our 
seeing  the  difference  between  one  seed  and  another, 
for  certainly  even  the  most  careless  observer  will 
admit  that  he  has  never  yet  found  two  perfectly 
identical  plants.  Not  even  two  peas,  taken  from  the 
same  pod,  will  grow  up  precisely  alike. 

But  as  long  as  the  seed  is  kept  from  its  natural  bed 


278  Chances  of  Life 

in  the  earth,  it  not  only  looks  dead,  but  is  dead  to  all 
intents  and  purposes,  for  it  has  no  means  of  showing 
that  it  lives — dead,  however,  with  a  possibility  of  life, 
which  generally  grows  less  and  less  the  longer  it  is  left 
unburied.  When  the  life  has  died  out  of  it  wholly, 
it  still  looks  much  the  same  as  before,  at  least  to  the 
unpractised  eye. 

As  to  living  seed,  if  it  be  one  that  we  know,  we  can 
tell  at  a  glance  what  sort  of  plant  bore  it,  and  what 
plant  will  spring  from  it.  But  if  it  is  a  seed  that  we 
do  not  know  ? 

Well,  even  then,  we  may  be  able  to  tell  by  the  look 
of  it  what  family  it  belongs  to,  whether  it  is  starchy 
or  oily,  whether  it  will  have  two  seed-leaves,  like  a 
bean,  or  one,  like  corn.  But  our  knowledge  will  not 
carry  us  much  further.  In  many  cases  it  will  not 
even  tell  us  whether  the  forthcoming  plant  will  be  a 
tree,  or  a  shrub,  or  a  lowly  herb.  To  the  inexpe- 
rienced, many  of  the  smaller  seeds  especially  look 
very  much  alike;  and  there  is  certainly  no  such  differ- 
ence in  their  appearance  as  would  lead  one  to  guess 
at  the  great  variety  of  plants  which  will  spring  from 
them ;  and  even  the  wisest  knows  very  little  about  the 
why  and  the  wherefore  of  the  matter. 

For  why  should  the  small  seed  of  the  elm  produce  a 
tall  tree,  r.nd  the  large  seed  of  the  gourd  only  a  short- 
lived, weak-stemmed,  creeping  plant  ?  Why  should 
one  bean  grow  to  the  height  of  a  few  inches  only  and 
another  climb  up  several  feet  ?  Why,  again,  should 
an  acorn  always  produce  an  oak  and  not  some  other 
tree  ?  All  that  we  can  answer  is,  an  acorn  has  oak- 
life  in  it.  But  we  might  as  well  say  we  don't  know, 
for  all  the  light  this  throws  upon  the  subject 


Chances  of  Life  279 

Look  now  at  these  seed-pods  and  seeds.  We  may 
know  that  they  have  been  taken  from  plants  of  the 
great  cabbage  family;  but  the  family  likeness  is  so 
strong  between  them  that  we  should  probably  be 
puzzled  to  say  which  would  produce  red  cabbages 
and  which  green,  and  from  which  will  come  crinkle- 
leaved  savoys,  curly -leaved  kale,  Brussels  sprouts, 
broccoli,  or  cauliflowers.  All  these  are  but  varieties 
of  the  cabbage,  though  they  are  so  very  different 
in  appearance;  and  as  long  as  they  are  only  seeds, 
they  are  so  nearly  alike  that  their  secret  is  quite  safe 
from  ordinary  people. 

Even  when  we  know  that  certain  plants  will  spring 
from  certain  seeds,  we  are  in  many  cases  quite  unable 
to  tell  what  the  colour  of  the  blossom  will  be.  There 
is  no  difference  at  all  to  be  detected  in  the  seed,  yet 
one  seed  will  produce  blossom  of  one  colour  and 
another  of  another.  But  why  ? 

For  instance,  from  the  seed  of  the  verbena,  phlox, 
and  sweet-pea,  we  know,  because  it  has  been  so  in  the 
past,  that  we  shall  get  verbenas,  phloxes,  and  sweet- 
peas  ;  and  we  may  go  a  step  beyond  this,  and  say  that 
there  will  be  no  quite  blue  flowers,  nor  any  yellow 
ones  among  them.  This  we  know  from  experience. 
We  know,  too,  that,  though  the  seeds  of  each  sort 
look  so  exactly  alike,  no  two  plants  will  be  absolutely 
similar,  and  the  blossoms  will  vary  much.  Some  of 
the  pea- blossoms  may  be  pink  of  different  shades, 
others  pink  and  white,  or  purple,  though  they  grow 
side  by  side ;  and  there  will  be  still  greater  variety  in 
the  colours  of  the  phloxes  and  verbenas,  some  of 
which  will  also  have  white  eyes  and  some  not.  But 


280  Chances  of  Life 

we  cannot  tell  by  looking  at  it  which  seed  will  produce 
which  blossom. 

And  even  if,  in  some  cases,  we  should  be  able  to  do 
this,  we  are  still  not  a  whit  nearer  solving  the  mystery 
of  the  how  and  the  why.  We  may  conclude  that  there 
is  some  minute  difference  in  the  food  which  the  roots 
take  up,  according  as  the  blossoms  are  of  one  colour 
or  another ;  for  we  know  that  the  pink  hydrangea  will 
turn  blue  if  supplied  with  an  extra  amount  of  iron ; 
and  we  may  argue  that,  though  the  peas  all  look  alike, 
one  has  that  within  it  which  causes  it  to  take  up  what 
will  produce  pink  blossoms,  and  another  that  which 
will  produce  purple  ones.  But  it  is  a  mystery  still. 

We  may  prevent  their  growing  at  all,  we  may  keep 
them  till  the  possibility  of  life  has  died  out  of  them ;  or, 
though  we  let  them  grow,  we  may  prevent  their  blos- 
soming ;  but  if  allowed  to  grow  and  blossom  without 
interference,  in  their  native  soil,  one  will  bear  its  pink, 
and  another  its  purple  blossoms  without  fail. 

But  if  the  seed  tells  us  nothing  as  to  the  colour  of  the 
blossom  which  will  spring  from  it,  it  often  tells  us  also 
just  as  little  as  to  the  size  of  the  plant  which  it  will 
produce,  and  the  length  of  that  plant's  life. 

Here,  for  instance,  are  three  seeds  of  different  sizes, 
but  all  belonging  to  the  bean-like  or  leguminous  order 
of  plants.  Supposing  that  we  had  never  seen  them 
before,  and  were  told  that  one  would  produce  a  tree, 
another  a  shrub,  and  the  third  a  dwarf  annual,  should 
we  be  likely  to  guess  that,  from  the  two  smaller  seeds, 
would  grow  a  laburnum  and  a  broom-plant,  while 
from  the  third,  which  is  so  many  times  larger,  would 
spring  only  a  broad,  or  Windsor,  bean  ? 

Some  of  the  orchids  bear  large  blossoms,  and  others 


Chances  of  Life  281 

large  masses  of  blossom ;  yet  their  seed  is  almost  dust- 
like.  The  seed  of  the  lobelia  and  of  the  scented 
tobacco  is  about  equally  minute;  but  from  the  one 
springs  a  plant  only  a  few  inches  high,  with  quite  small 
blossoms ;  and  from  the  other,  one  which  grows  to  a 
height  of  two  or  three  feet,  and  has  blossoms  at  least 
four  inches  long. 

Then,  again,  size  of  seed  has  nothing  at  all  to  do 
with  length  of  life.  The  large  broad  bean  has  life  only 
for  a  single  season ;  the  small  laburnum-seed  has  life 
which  lasts  for  years.  The  lupin,  another  leguminous 
plant,  is  both  an  annual  and  a  perennial ;  but,  strange 
to  say,  the  perennial  lupin  bears  the  smaller  seed, 
though  it  not  only  lives  longer  but  is  also  the  taller 
plant,  and  produces  more  blossom  of  the  two. 

An  oak  may  live  as  many  centuries  as  a  bean  does 
months,  or  more ;  but  who  can  say  why  ? 

The  famous  chestnut-tree  on  Mount  Etna  is  said  to 
be  1,000  years  old  ;  and  among  other  ancient  trees, 
whose  age  is  more  or  less  well  attested,  there  is  an 
oak  reputed  to  be  1,600  years  old  and  a  walnut  of  900; 
there  are  olives  which  are  believed  to  be  2,000  years 
old ;  and  there  is  at  least  one  tree  in  the  East  which 
tradition  affirms  to  be  even  6,000  years  old  !  But, 
again,  why  an  olive  should  outlive  an  oak,  who 
can  say  ? 

There  is  a  great  difference,  also,  as  to  the  length 
of  time  during  which  the  seeds  themselves  retain  their 
vitality  or  power  of  germinating.  Most  of  them  look 
equally  lifeless ;  but  in  some  this  mysterious  power 
lasts  much  longer  than  in  others,  and  this,  too,  with 
very  little  reference  to  their  size,  though  large  seeds, 
especially  oily  seeds,  have  some  advantage.  The  seed 


282  Chances  of  Life 

of  the  coffee-berry,  for  instance,  is  worthless  unless 
planted  without  delay  directly  it  is  ripe ;  and  willow- 
seed  is  said  to  live  only  a  fortnight  after  ripening,  or 
less,  if  it  is  allowed  to  become  dry.  Seeds  of  melon 
and  geranium,  on  the  other  hand,  have  been  known  to 
germinate  after  being  kept,  merely  wrapped  in  paper, 
for  thirty  years.  It  is  believed  that,  if  melon-seeds 
produce  plants  at  all,  after  being  kept  for  some  time, 
their  crop  of  fruit  will  be  all  the  larger ;  but  they  are 
commonly  supposed  not  to  live  longer  than  seven 
years,  and  even  within  this  period  the  longer  they  are 
kept  the  smaller  is  their  chance  of  germinating  con- 
sidered to  be. 

Cases,  however,  have  been  known  in  which  certain 
seeds,  quite  small  seeds,  too,  have  kept  the  life  in  them 
not  only  for  years  but  for  centuries,  and  evei*  millen- 
niums. We  are  not  alluding  to  the  famous  mummy 
wheat ;  for  the  grain  of  wheat,  being  quite  unprotected 
Except  by  a  thin  husk,  loses  all  power  of  germinating 
in  a  few  years  at  most ;  and  none  of  the  interesting 
stories  told  of  wheat  raised  from  grain  found  in 
Egyptian  tombs  have  ever  yet  been  satisfactorily 
proved. 

Grain  taken  from  mummies  has  germinated  sure 
enough,  but  it  has  been  grain  recently  introduced  by 
the  Arabs  !  In  one  instance  the  plant  raised  bore 
oats  ;  but  this  was  unlucky,  for  oats  were  not  known  to 
ancient  Egypt ;  and  in  no  single  case  has  any  success 
attended  the  innumerable  attempts  made  to  raise 
plants  from  genuine  mummy  wheat.  But  seeds  found 
in  Roman  tombs  have  not  only  germinated,  but  pro- 
duced plants. 

Of  all  well-authenticated  cases,  however,  the  most 


Chances  of  Life  283 

remarkable  is  that  of  the  seedlings  raised  by  Dr. 
Lindley,  in  Chiswick  Gardens,  from  raspberry-seeds 
found  in  Celtic  tumuli  perhaps  some  two  thousand 
years  old.  Raspberry-seeds  have  very  hard  coats,  it  is 
true,  and  these  seeds  were  safely  buried  from  the  air, 
and  beyond  the  reach  of  any  great  changes  of  temper- 
ature ;  but  yet  that  things  so  small  should  have  been 
able  to  preserve  living  germs  within  them  for  so  long  a 
time  is  a  wonderful  proof  of  their  great  tenacity  of 
life. 

Generally  speaking,  it  seems  that  the  seeds  of  wild 
plants  have  the  advantage  over  the  cultivated  in  this 
respect.  They  retain  their  vitality  longer ;  but  then, 
on  the  other  hand,  there  are  not  so  many  of  them. 
Cultivated  plants  usually  produce  most  seed — except, 
of  course,  where  blossoms  have  been  doubled  or  fruit 
improved  at  its  expense. 

When  one  considers  the  vast  quantity  of  seed  pro- 
duced, and  the  ample  contrivances  for  scattering  it,  it 
is  surprising  to  find  that,  after  all,  many  plants  do  not 
increase  their  numbers  at  all.  There  are  just  about  the 
same  number  of  them  now  that  there  were  years  ago — 
neither  more  nor  fewer. 

Take,  for  example,  the  common  wild  spotted  orchis, 
a  single  plant  of  which  often  bears  as  many  as  thirty 
seed-vessels,  each  containing  6,200  seeds.  Suppose  that 
there  were  400  bad  seeds  to  each  capsule,  12,000  in  all, 
which  is  a  fair  allowance,  one  plant  might  still  be  the 
parent  of  174,000  others — enough  to  cover  nearly  an 
acre  of  ground  if  the  plants  grew  just  far  enough  apart 
to  allow  a  proper  amount  of  space  to  each.  The  de- 
scendants of  these,  again,  might  more  than  cover  the 


584  Chances  of  Life 

Isle  of  Anglesey,  and  the  great-grandchildren  of  the 
one  original  plant  would  more  than  clothe  the  entire 
land-surface  of  the  globe  ! 

This  calculation  was  made  by  Mr.  Darwin  ;  and  yet, 
as  he  goes  on  to  observe,  the  plant  is  actually  not  in- 
creasing at  all  in  most  places,  although  it  is  a  perennial, 
and  although  its  seeds  are  so  minute  as  to  be  easily 
wafted  to  a  great  distance  by  the  wind.  So,  then,  only 
one  seed  out  of  the  thousands  borne  by  a  single  plant 
can  come  to  anything,  and  even  that  not  every  year, 
but  only  once  in  several  years ;  for,  as  each  plant  lives 
some  years,  there  must  be  an  increase  in  its  numbers 
if  but  one  new  plant  grew  up  every  year. 

That  the  seeds  are  scattered,  and  widely  scattered,  is 
unquestionable,  for  seedlings  have  been  found  eight  or 
ten  miles  away  from  where  any  plants  grew ;  but  it  is 
equally  certain  that  there  is  some  effectual  check  to 
the  plant's  increase,  though  what  that  check  is  remains 
unknown. 

It  is  plain,  therefore,  that  the  mere  scattering  of  the 
seed,  however  necessary  as  a  first  step,  is  far  from 
being  enough  to  secure  that  the  plant  shall  be  able  to 
establish  itself  in  a  fresh  locality ;  and  the  farther  the 
seed  is  carried  the  greater  the  risk  it  often  runs.  Some 
plants  are  much  better  able  than  others  to  adapt  them- 
selves to  altered  circumstances,  and  these,  of  course, 
make  the  better  colonists  ;  but  even  they  may  be  quite 
unable  to  effect  a  settlement  simply  for  lack  of  space. 
Others  find  that  soil,  or  climate,  or  situation  do  not 
suit  them,  and  soon  die  out  for  that  reason.  Others, 
again,  though  they  may  find  ample  room,  and  all 
things  else  to  their  liking,  are  quite  unable  to  become 
permanent  colonists  because  they  cannot  fertilize  them- 


Chances  of  Life  285 

selves,  and,  if  there  are  not  the  right  insects  to  do  it 
for  them,  they  cannot  produce  any  seed.  Such  plants 
as  have  more  than  one  '  form  '  (see  p.  222),  and  such  as 
bear  pollen  and  ovules  on  separate  individuals,  run,  of 
course,  especial  risks  when  they  migrate,  as  one  is 
generally  helpless  without  the  other. 

In  the  matter  of  soil,  too,  a  very  short  distance  often 
makes  a  great  difference.  The  bee-orchis  for  example, 
grows  plentifully  on  the  chalk  in  Surrey,  and  one  year 
it  suddenly  made  its  appearance  in  a  clayey  field  near 
Thames  Ditton,  where  it  had  never  been  seen  before. 
About  a  hundred  plants  blossomed  in  this  one  field, 
and  nowhere  else  in  the  neighbourhood.  But  they 
gradually  dwindled  away,  and  in  the  course  of  six  or 
eight  years  all  had  entirely  disappeared.  The  seeds 
had  probably  travelled  to  the  clay-field  in  some  chalk 
which  had  been  brought  from  another  part  of  the 
county,  but  the  colony  could  not  be  a  lasting  one  for 
some  reason — most  likely  owing  to  the  change  of  soil, 
and  perhaps  also  of  situation. 

Then,  again,  there  is  the  milk-thistle,  which  has  run 
riot  in  Australia,  but  has  utterly  failed  to  make  a  settle- 
ment in  New  Zealand.  Single  specimens  have  been 
grown  in  the  latter  country,  and  have  seeded  freely. 
The  seeds,  too,  after  the  manner  of  their  kind,  must 
have  been  carried  hither  and  thither  by  the  wind  in 
multitudes  ;  but  .still  the  plant  has  not  spread,  and  is  a 
failure — a  fortunate  failure — as  an  emigrant. 

Other  European  plants,  to  the  number  of  more  than 
a  hundred  and  fifty,  have  been  quite  successful  in  New 
Zealand,  and  are  thoroughly  established ;  but,  it  is  re- 
markable that,  while  so  many  European  plants  have 
made  themselves  at  home  there,  only  two  or  three 


286  Chances  of  Life 

Australians  have  managed  to  do  so.  Yet  Australia  is 
nearer  than  Europe,  and  the  intercourse  between  the 
two  countries  is  much  more  close  and  frequent  than  it 
is  with  Europe.  Moreover,  Australian  seeds  have  been 
purposely  and  extensively  scattered  in  New  Zealand, 
among  them  being,  we  may  be  sure,  the  seeds  of  such 
common  kinds  as  those  of  the  acacia  and  eucalyptus ; 
yet  none  of  these  trees  are  to  be  seen  growing  wild. 

It  is  the  same  with  our  own  garden-plants.  How 
many  there  are  which,  though  they  grow  in  the  garden 
without  any  special  care,  and  bring  abundance  of  seed 
to  perfection,  yet  never  run  wild,  even  to  the  extent  of 
appearing  on  just  the  other  side  of  the  wall  or  hedge  ! 
Yet  it  is  impossible  to  suppose  but  that  the  seed  is 
often  carried  beyond  these  limits ;  and  weeds  make 
their  way  in  without  difficulty. 

In  considering  what  becomes  of  the  vast  amount  of 
seed  which  is  annually  ripened,  we  must,  of  course, 
bear  in  mind  that  a  great  deal  is  consumed  as  food — 
luckily  for  us ;  for  if  there  were  no  seed-eating  birds, 
we  should  be  overrun  with  thistles  and  other  weeds. 
Some  seed  also  falls  upon  soil  which  does  not  suit  it ; 
some  requires  burying,  and  gets  killed  by  remaining 
exposed ;  some  cannot  germinate  without  special  pre- 
paration of  itself  or  the  soil,  or  both  ;  still  more,  if 
transported  to  a  distance,  will  find  the  climate  unsuit- 
able. 

But  in  many  cases  want  of  space  is  the  only  obstacle, 
and  a  very  serious  one  it  is.  There  is  generally  plenty 
of  room  for  weeds  in  a  garden,  and  they  are  not  slow 
to  take  advantage  of  it ;  for  there  is  a  good  deal  of 
crowding  on  the  other  side  of  the  wall,  where,  in  fact, 
a  constant  struggle  for  existence  is  going  on,  and  only 


Chances  of  Life  287 

the  stronger  survive.  Seeds  falling  upon  ground  already 
covered,  and  thickly  covered,  with  vegetation,  as  a 
hedge-bank  generally  is,  have  but  little  chance  In  fact, 
they  hardly  reach  the  soil  at  all,  the  great  majority  of 
them. 

Look  among  the  long  meadow-grass,  and  you  may 
often  see  hundreds  and  thousands  of  downy  seeds 
caught  among  the  stems  and  suspended,  each  wi*h  its 
seed  pointing  downwards,  ready  to  take  advantage  of 
any  crack  in  the  soil  in  which  to  insert  itself,  but  quite 
unable  and  unlikely  to  reach  it.  And  even  of  the  seeds 
which  do  reach  it,  how  many  must  find  that  the  first- 
comers  are  stronger  and  better  fitted  for  the  situation 
than  themselves  !  and  so,  even  if  they  spring  up,  they 
are  speedily  overpowered  and  crowded  out. 

This,  of  course,  is  especially  the  case  with  such  seeds 
as  are  transported  long  distances  and  to  other  quarters 
of  the  world,  where  the  chances  are  that  they  will  find 
the  soil  already  occupied  by  natives,  among  whom  they 
will  be  choked.  Should  they  find  a  bare  spot,  however, 
and  soil  and  climate  suitable,  they  will  still  be  unable 
to  do  more  than  effect  a  temporary  settlement — will 
not,  in  fact,  become  really  naturalized — unless  the 
plants  can  either  fertilize  themselves  or  find  insects 
able  to  do  the  work  for  them.  In  the  matter  of  space, 
those,  of  course,  have  a  great  advantage  which  grow 
upon  others,  as  fresh  surfaces  are  being  constantlv  pre- 
pared for  them. 

The  number  of  seeds  produced  varies  enormously  in 
different  plants.  Orchids  produce  them  at  the  rate  of 
thousands  to  each  blossom ;  and  some  of  the  foreign 
species  go  far  beyond  this,  a  single  seed-vessel  con- 
taining more  than  a  million  and  three-quarters  of  seeds. 


288  Chances  of  Life 

The  blossom  of  an  oak,  on  the  other  hand,  produces 
but  one  seed.  But  the  advantage  is  not  all  on  the  side 
of  numbers ;  for  the  greater  the  number,  the  smaller 
the  size;  and  the  smaller  the  seed,  the  smaller  the 
germ,  and  also  the  smaller  the  supply  of  ready-made 
food  with  which  it  begins  life.  A  large  seed,  such  as  a 
bean,  has  a  large,  strong  germ ;  and  its  two  thick  seed- 
leaves,  which  are  really  store-cupboards,  can  supply 
the  seedling  with  plenty  of  food,  so  that  it  starts  with 
much  in  its  favour.  And  so  ten  large  seeds  will  often, 
it  is  said,  yield  more  plants  than  some  thousands  of 
small  ones.  One  may  also  conjecture  that,  when  an 
ovary  contains  ovules  by  the  thousand,  or  million,  each 
requiring  the  contents  of  two  or  three  grains  of  pollen 
at  least,  and  some  as  many  as  twenty,  it  is  not  unlikely 
that  some  will  be  left  out,  and,  failing  to  get  what  they 
want,  will  not  succeed  in  becoming  true  seeds  at  all. 

One  perfect  seed  to  each  plant  in  the  course  of  its 
life  is  enough  to  ensure  that,  at  all  events,  it  shall 
neither  die  out  nor  suffer  any  decrease  in  its  numbers ; 
but  while  the  oak  will  be  able  to  hold  its  own  if  it  have 
but  one  sound  acorn  in  the  course  of  a  few  hundred 
years,  the  chickweed  must  have  one  good  seed  every 
year,  if  it  is  to  keep  up  its  numbers.  This,  of  course, 
is  supposing  that  the  one  seed  is  allowed  to  produce  a 
seedling,  and  the  seedling  to  grow  up  into  a  plant ; 
but,  as  much  seed  and  many  seedlings  are  devoured, 
many  more  are  actually  required. 

Neither  the  acorn,  nor  the  chestnut  when  it  has  left 
its  shell,  has  anything  to  protect  it,  except  its  colour, 
which  being  like  that  of  the  earth,  or  of  dead  leaves, 
may  sometimes  enable  it  to  escape  notice  as  it 
lies  on  the  ground;  and  if  but  one  escapes  now 


Chances  of  Life  289 

and  then,  at  long  intervals,  once  in  a  few  centuries,  the 
stock  will  be  kept  up,  though  not  increased. 

Small  seeds  have  a  better  chance  in  some  ways,  as 
they  are  more  easily  sheltered,  and  hidden  from  the 
bright  keen  eyes  of  the  birds.  A  bed  of  damp  moss  is 
a  capital  hiding-place;  and  so  are  the  cracks  which 
open  in  the  soil  when  the  earth  is  dry ;  for  these  close 
up  again  when  the  wet  comes,  and  the  seeds  are  safely 
buried  out  of  harm's  way.  Cracks  may  often  be  seen 
full  of  seeds. 

Still,  '  if  you  want  a  thing  done,  do  it  yourself,'  is  an 
excellent  motto  even  for  seeds,  and  it  is  an  advantage 
to  be  independent  even  of  cracks !  This  is  what  some 
seeds  are,  especially  a  good  many  grass-seeds;  for 
instead  of  waiting  to  be  buried,  they  set  to  work  and 
bury  themselves. 

The  seed  of  the  grass  Aristida,  for  instance,  is 
enclosed  in  a  couple  of  husks  tipped  with  bristles,  each 
divided  into  three  fine  tails,  six  or  eight  inches  long, 
which  stand  out  in  different  directions  more  or  less  at 
right  angles  to  the  seed.  When  the  seed  falls  to  the 
ground  the  tails  keep  it  upright,  and  as  they  dry  and 
twist,  they  make  it  turn  round  and  round  on  its  point, 
which  is  barbed  with  flint ;  and  so  it  bores  its  way 
into  the  earth,  the  barb  holding  it  fast,  so  that  it  cannot 
be  blown  away  by  wind. 

Another  self-burying  seed  is  that  of  one  of  the 
Cranesbills,  which  is  nearly  related  to  the  geranium. 
The  fruit  of  this  little  plant  consists  of  four  or  five 
miniature  arrows,  which  are  the  hardened  and  much 
lengthened  carpels,  each  having  its  ovary  (containing  a 
single  seed)  at  the  lower  end.  At  first  they  are  fitted 
closely  together  round  a  central  spike,  and  form  the 

19 


290  Chances  of  Life 

'beak*  with  which  we  are  all  familiar  in  the  geranium. 
But  when  they  are  ripe,  they  separate  at  the  lower  end, 
and  begin  to  twist  like  a  corkscrew,  still  holding  together 
at  the  tip,  however,  for  a  time.  Each  arrow  is  fringed 
on  the  inner  side  with  short  stiff  hairs,  and  the  ovary 
is  pointed  and  barbed  in  a  special  manner.  They  are 
readily  carried  by  the  wind  therefore,  besides  also 
clinging  easily  to  the  coats  of  animals ;  and  when  at 
last  they  drop  singly  to  the  ground,  the  barbs  catch  in 
the  soil  and  hold  them  fast.  The  shafts  of  the  arrows 
twist  more  and  more  the  drier  they  grow,  and  as  they 
twist,  they  turn  the  seed  deeper  and  deeper  into  the 
ground. 

Some  seeds  have  many  more  difficulties  in  the  way 
of  their  growing  than  others.  For  with  some,  it  is 
absolutely  necessary  that  they  should  be  buried  before 
they  can  even  begin  to  germinate ;  while  others,  though 
they  may  be  able  to  germinate  without  help  or  pre- 
paration of  any  kind,  find  it  by  no  means  easy  to  do 
more  than  make  the  first  start. 

With  some,  germination  is  an  easy  matter  enough, 
all  that  they  need  being  a  little  moisture.  Such  is  the 
mustard-seed,  which  will  sprout,  and  even  grow  for  a 
time,  on  any  damp  surface ;  a  piece  of  flannel,  or  even 
the  outside  of  a  porous  earthenware  jar  will  do,  if  only 
this  is  kept  filled  with  water.  Other  seeds  begin  to 
shoot  even  before  they  leave  the  parent-plant.  The 
seeds  of  a  species  of  convolvulus  put  forth  quite  large 
leaves  before  they  burst  the  pod ;  and  in  hot  climates, 
the  seed  of  the  water-melon  sometimes  grows  in  like 
manner,  within  the  fruit. 

Brazil  nuts  also  begin  sprouting  before  the  hard 
outer  case  in  which  they  are  enclosed  shows  any  sign 


Chances  of  Life  291 

of  decay ;  but  though  they  may  all  sprout,  only  one  of 
the  whole  number  seems  to  have  a  chance  of  doing 
more  under  ordinary  circumstances.  There  are  from 
twelve  to  fifteen  nuts — or,  strictly  speaking,  seeds — in 
each  ovary  or  case,  which  is  rilled  with  the  matted 
roots  sent  out  by  one  and  all.  At  the  lower  end,  where 
the  fruit  was  attached  to  the  stalk,  there  is  a  small 
opening,  and  the  fortunate  individual  which  gains  pos- 
session of  this  exit  may  eventually  burst  the  case  with 
its  roots,  and  so  make  its  way  into  the  soil.  But  the 
shell  of  the  case  is  extremely  hard,  and,  so  far  as  has 
been  observed,  it  is  not  often  that  even  one  single 
plant  succeeds  in  freeing  itself.  But  then,  on  the  other 
hand,  if  the  shell  were  less  hard,  none  would  probably 
ever  escape  the  hosts  of  animals  ready  to  devour  them ; 
for  sprouted  nuts,  taken  out  of  the  case  and  planted, 
have  been  found  to  be  all  dug  up  and  en  *  t:n  by  rats. 

Such  are  the  difficulties  of  the  Brazil  nuts ;  but  other 
seeds  have  equal,  if  different,  obstacles  to  contend  with. 
Many,  if  they  escape  being  devoured,  are  still  quite 
unable  to  grow  as  long  as  they  are  left  lying  on  the 
surface  of  the  ground,  especially  when  that  surface  is 
covered  with  the  leaves  of  the  parent  tree. 

With  the  exception  of  the  sugar-maple,  none  of  the 
forest-trees  or  the  evergreens  seem  to  have  children 
growing  up  round  them  in  Indiana.  Seeds  of  white 
pines,  firs,  American  poplars,  etc.,  when  they  fall  upon 
the  scattered  leaves  of  the  parent  tree,  simply  lie  there 
and  die ;  and  their  almost  only  chance  of  life  seems  to 
be  when  they  fall  upon  some  little  bed  of  earth  made 
by  the  hogs,  which  root  about  among  the  leaves  and 
turn  up  mould  while  they  are  searching  for  worms. 

One  would  not  suspect  hogs  of  doing  any  useful 


292  Chances  of  Life 

work  of  this  sort ;  but  these  animals,  which  have  been 
turned  loose  in  the  woods,  do  seem  to  have  planted 
many  clusters  of  young  poplars,  for  the  age  of  the 
trees  just  corresponds  with  the  date  when  the  pigs 
were  first  brought  into  the  settlement. 

Other  animals,  such  as  squirrels,  also  give  similar 
help  by  digging  through  the  leaves ;  and  the  hoofs  of 
bullocks  make  deep  tracks  in  the  ground,  in  which  any 
falling  seeds  have  a  fair  prospect  of  rooting  them- 
selves. 

A  change  deserving  of  notice  has  been  wrought  in 
some  parts  of  the  Riverina,  New  South  Wahs,  solely, 
as  it  would  seem,  by  the  introduction  of  cattle.  In  the 
old  times  there  were  not  animals  enough  to  eat  the 
grass  down ;  and  so,  when  it  became  ripe  and  dry,  it 
was  easily  set  alight  by  a  chance  spark  from  the  fire  of 
a  native.  The  natives  were,  indeed,  suspected  of  firing 
it  on  purpose,  to  ensure  a  fresh  crop  to  tempt  the 
kangaroos  within  their  reach.  Any  seeds  of  eucalyptus 
or  other  trees  were  either  killed  in  the  conflagration  or 
by  exposure  the  weather,  for  they  lay  on  the  surface 
of  the  ground,  with  no  animal  sufficiently  heavy  of  foot 
to  tread  them  in  ;  and  it  would  seem  that  their  only 
hope  could  be  in  chance  cracks.  Trees  were  accord- 
ingly scarce  in  these  parts ;  but  the  scarcity  evidently 
arose,  not  from  want  of  seed,  but  from  want  of  oppor- 
tunity for  its  growth.  For  all  now  is  altered:  the 
cattle  tread  the  seeds  in,  and  don't,  apparently,  eat 
the  young  plants  which  spring  from  them  ;  for  dense 
forests  and  scrubs  have  arisen — not  to  the  satisfaction 
of  the  graziers,  who  would  prefer  grass  alone. 

Some  .seeds  appear  to  have  only  an  occasional  chance 
of  germinating  in  a  state  of  nature;  for  they  must 


Chances  of  Life  293 

either  be  scalded,  or  scorched,  or  very  hard  frozen 
before  they  can  sprout  at  all,  and  even  then  they 
cannot  prosper  unless  they  have  a  clear  field,  with  no 
other  plants  to  interfere  with  them.  This  is  the  case 
with  the  seeds  of  the  black  locust-tree,  which  are  easily 
carried  by  the  wind,  and  are  so  very  hard  that  they 
may  lie  exposed  for  years  without  being  any  the  worse 
for  it,  it  is  true,  but  also  without  being  able  to  ger- 
minate. If  they  were  less  long-lived,  they  would 
probably  die  before  their  opportunity  came.  But  if, 
when  a  clearing  is  made  in  the  forest,  the  trees  should 
be  fired  and  the  ground  burnt  bare,  as  it  is  sometimes, 
then  comes  their  long-waited-for  opportunity,  and  up 
they  spring  in  numbers  wherever  the  fire  has  passed. 

The  same  thing  is  true  in  some  degree  of  the  Tas- 
manian  '  fire-weed,'  a  thick  crop  of  which  springs  up 
like  magic  wherever  even  a  camp-fire  is  made,  but 
never  except  where  fire  has  passed  over  the  ground. 
The  plant,  which  is  nearly  related  to  the  groundsel  and 
cineraria,  has  downy  seeds,  which  would  not,  of  course, 
stand  the  fire ;  but  the  wind  is  constantly  carrying 
them  to  and  fro,  and  wherever  there  is  a  spot  properly 
prepared  for  them  they  take  immediate  advantage  of 
it.  Numbers  must  perish  while  they  are  waiting  for  an 
opportunity  which  never  comes ;  but  still  there  are 
always  enovgh  left  to  take  possession  of  any  bare, 
burnt  space. 

The  seeds  of  a  certain  species  of  cedar  could  not  be 
got  to  grow  at  all  at  the  Cape  until  they  had  been 
thoroughly  I  oiled.  Such  very  hard-coated  seeds  are 
well  protected  against  injury,  but  in  a  state  of  nature 
they  must  be  dependent  upon  fires,  frost,  or  perhaps 
on  being  swallowed,  for  the  opportunity  of  growing. 


294  Chances  of  Life 

Other  seeds,  again,  though  they  require  no  special 
preparation  of  themselves  or  the  soil,  are  quite  unable 
to  germinate  unless  they  get  rain  immediately  after 
they  have  fallen,  and  that,  too,  continued  for  some 
little  time. 

Thus  the  'soft  maples'  planted  in  the  streets  of 
Rockville,  Indiana,  though  they  have  borne  seed,  have 
never  succeeded  in  sowing  themselves  till  within  the 
last  few  years,  as  a  single  day's  exposure  to  the  hot  sun 
is  fatal  both  to  seeds  and  seedlings,  and  even  daily 
watering  often  proves  insufficient  to  keep  the  latter 
alive.  In  the  wild  state  they  spring  up  only  in  very 
moist  or  watery  places,  though  later  on  they  will  bear 
transplanting  to  dry  soil. 

One  year,  however,  there  was  a  storm  which  shook 
down  such  a  quantity  of  seed  that  the  streets  of  Rock- 
ville were  yellow  with  it.  Then  followed  several  days' 
rain,  with  sunny  intervals,  and  the  seeds  sprouted 
everywhere,  all  over  the  streets,  in  the  yards  and  the 
gardens,  as  thick  as  weeds  —  a  sight  never  seen 
before. 

But  the  cows  ate  those  in  the  streets,  human  beings 
weeded  out  those  in  the  gardens,  and  the  summer 
drought  killed  the  rest ;  so  that,  of  all  the  millions 
which  started  into  life,  only  one  clump  remains,  and 
these  owe  their  survival  to  the  fact  that  they  are  not 
only  out  of  the  reach  of  animals,  but  in  a  damp  spot 
near  a  drain. 

To  be  beyond  the  reach  of  animals  makes,  as  Mr. 
Darwin  has  pointed  out,  an  all-important  difference  in 
the  seedling's  chance  of  life ;  and  he  mentions  the  case 
of  an  extensive  heath  near  Farnham,  in  Surrey,  part  of 
tvhich  was  enclosed,  and  part  not.  Within  the  enclo- 


Chances  of  Life  295 

sure  multitudes  of  seedling  trees  were  to  be  seen ; 
outside,  none.  Yet  they  were  there,  plenty  of  them, 
striving,  but  failing,  to  get  their  heads  above  the 
heather,  because  perpetually  browsed  down  by  the 
cattle.  One  aged  seedling,  three  inches  high,  had  been 
making  persevering  but  fruitless  efforts  for  six-and- 
twenty  years,  so  it  seemed,  from  the  number  of  its 
annual  rings ;  and,  but  for  the  cattle,  the  heath  would 
quickly  have  become  a  wood. 

Space,  as  we  have  said,  is  a  matter  of  prime  import- 
ance, and  the  reason  why  tropical  ferns  and  orchids 
have  been  so  successful  in  establishing  themselves  in 
the  islands  of  the  Southern  Ocean  is  not  only  because 
their  seeds  are  plentiful  and  easily  carried,  but  because, 
as  they  can  grow  upon  other  plants,  they  are  never  at  a 
loss  for  vacant  spots. 

Bare  spaces  are  otherwise  not  of  frequent  occurrence 
in  nature,  except  on  mountains,  where  landslips  on  a 
large  or  small  scale  are  often  taking  place  and  exposing 
fresh  surfaces.  These  are  quickly  sown  with  seeds 
either  by  the  winds  or  by  the  birds,  and  hence  moun- 
tain chains  are  very  common  routes  by  which  plants 
travel,  gradually  making  their  way  along  them  by  easy 
stages.  Railway  embankments,  too,  are  turned  to 
similar  account ;  and  people  are  sometimes  surprised 
to  see  these  occupied  for  a  time  by  plants  which  are 
quite  strangers  to  the  neighbourhood,  the  fact  being 
that  the  seeds,  though  scattered,  have  never  before  had 
the  luck  to^fall  on  a  free  space.  Plants  which  thus 
gain  a  footing  may  or  may  not  be  able  to  keep  it ;  they 
may  be  overpowered  by  the  natives  of  the  locality,  but 
even  so,  if  they  blossom  and  bear  fruit  but  once,  they 
have  gained  an  onward  step,  a  fresh  centre  from  which 


296  Chances  of  Life 

to  disperse  themselves,  and  so  they  may  make  a  gradual 
advance. 

How  is  it  that  European  weeds  have  spread  so  ex- 
tensively in  the  United  States,  while  Australian  seeds, 
widely  and  purposely  scattered  in  New  Zealand,  have 
gained  no  footing  ? 

First  and  chiefly  because  in  tne  one  case  there  was 
a  vacancy,  and  in  the  other  there  was  none.  The 
vacancy  in  America  was  not  natural,  but  caused  by  the 
cutting  down  of  forests  and  the  dying  off  of  the  under- 
growth, which  was  killed  by  sudden  exposure.  Of 
course,  there  were  plenty  of  plants  in  America  which 
would  have  stepped  in  and  taken  possession  in  time, 
but  they  were  too  far  off,  on  the  plains  and  prairies  of 
the  great  Mississippi  Valley,  to  do  it  quickly  enough, 
and  meantime  the  foreigners  arrived.  Weeds  from 
Europe  were  introduced  with  grass  seed  and  corn 
seed,  and  in  other  ways,  and  when  the  forest  lands 
were  turned  into  pastures  and  fields,  these  weeds  had 
as  good  a  chance  of  thriving  as  they  had  at  home. 

It  would  be  a  different  matter  if  they  were  to  arrive 
now,  for  meantime  other  changes  have  taken  place 
which  have  made  it  easier  for  plants  to  come  from  the 
west,  and  they  do  come.  New  western  plants  migrate, 
it  is  said,  almost  every  year  into  the  eastern  states. 

And  how  do  these  new  plants  travel  ?  By  rail,  to 
be  sure,  in  accordance  with  the  spirit  of  the  age.  They 
come  in  the  coats  or  in  the  food  of  cattle  going  to 
market,  and  they  take  advantage  of  the  bared  railway 
borders,  which  are  such  excellent  nursery-grounds. 
The  great  railroads  run  east  and  west,  and  as  the  pre- 
vailing winds  are  westerly  and  very  strong,  the  plants 
of  the  west  are  now  amply  provided  with  the  means  of 


Chances  of  Life  297 

transport.  The  seeds  also  find  vacant  spots  on  which 
to  alight,  and  by  which  they  may  break  the  journey, 
and  finally  they  are  transported  into  a  climate  not 
greatly  unlike  their  own,  so  that  they  have  much  in 
their  favour. 

Plants  travelling  east  and  west  have  a  much  better 
chance  of  finding  a  climate  to  suit  them  than  those 
which  travel  north  and  south,  except,  of  course,  such 
as  cannot  thrive  without  sea  air,  like  the  holly,  which 
cannot  live  at  all  more  than  a  hundred  miles  from  the 
coast.  But  of  the  plants  which  travel  north  and  south, 
those  generally  have  the  better  chance  which  travel 
from  a  cold  climate  to  a  warmer  one.  Increased 
warmth  is  better  borne  than  increased  cold,  and  the 
plants  of  temperate  latitudes  have  stronger  and  more 
vigorous  constitutions,  such  as  give  them  great  ad- 
vantages. 

See,  for  instance,  how  they  have  thriven  in  the 
Pampas  district  of  South  America,  in  some  parts  of 
which  there  is  hardly  a  native  plant  to  be  seen  for 
miles,  so  completely  have  the  new-comers  ousted  them. 
For  the  giant '  thistles '  and  the  luxuriant  clover  already 
described,  are  not  natives,  but  colonists.  The  father- 
land of  the  artichoke  family,  to  which  this  'thistle* 
belongs,  is  on  the  shores  of  the  Mediterranean,  and 
from  thence  '  thistles '  and  clover  were  probably  intro- 
duced by  the  Spaniards.  And  they  not  only  found  the 
soil  and  climate  suitable,  but,  a  still  greater  point  in 
their  favour,  they  found  the  ground  very  scantily 
occupied  by  native  vegetation. 

There  had  not  been  time  to  plant  this  corner  of  the 
world's  farm  thoroughly,  for  it  had  been  under  water 
until  comparatively  recent  times — recent,  geologically 


Chances  of  Life 

speaking,  that  is.  And  when  it  became  dry  land  there 
were  few  plants  and  no  trees  at  hand  to  colonize  it. 

There  was  abundant  vegetation  to  the  north,  however, 
and  that  of  the  most  luxuriant  kind,  and  most  of  the 
early  colonists  came  from  there.  But  they  were  too 
delicate  to  bear  well  the  change  to  such  much  cooler 
regions,  and  only  a  few  managed  to  settle  down  and 
really  flourish;  so  that  when  the  Europeans  came, 
strong  and  vigorous,  they  soon  overpowered  these 
previous  colonists,  which  had  but  scantily  occupied  the 
ground,  and  themselves  grew  in  a  rampant  manner. 
Any  delicate  new-comers  arriving  after  such  sturdy 
emigrants  as  these  would  naturally  have  no  chance 
at  all. 

The  air  of  Europe  seems,  indeed,  to  give  its  natives, 
both  men  and  plants,  a  wonderful  power  of  pushing  their 
way  and  standing  almost  any  climate,  and  they  are  to 
be  found  in  almost  all  parts  of  the  world. 

The  greater  the  distance  to  which  seeds  are  trans- 
ported, the  greater  usually  the  risk  they  run  of  meeting 
with  some  difficulty  in  the  way  of  their  permanent 
settlement. 

They  may  find  a  vacant,  or  almost  vacant,  spot, 
and  they  may  like  the  soil  and  even  the  climate,  but 
if  they  are  dependent  upon  any  particular  insect  for 
fertilization  they  will  not  be  able  to  perfect  their  seed 
without  it ;  and  if  they  cannot  do  this  they  can  never 
become  naturalized,  and  must  needs  in  most  cases 
die  out. 

The  vanilla  plant,  introduced  into  the  East  Indies 
from  tropical  America,  thrives  perfectly  up  to  a  certain 
point,  but  cannot  at  present  run  wild  ;  for  being  unable 
to  fertilize  itself,  and  finding  no  insects  to  do  the  work, 


Chances  of  Life  299 

it  depends  entirely  upon  man's  artificial  aid.  In  time, 
it  is  true,  the  difficulty  might,  and  may,  be  overcome, 
as  it  has  been  in  the  case  of  some  other  plants,  either 
by  their  becoming  self-fertilizing,  or  by  the  insects  of 
their  adopted  country  becoming  accustomed  to  them ; 
but,  in  the  meantime,  without  man  it  would  die  out. 

Of  plants  which  require  help,  those  are  most  likely 
to  prosper  whose  blossoms  are  least  peculiar  in  shape 
and  most  easily  got  at.  Tubular  blossoms,  such  even 
as  the  common  clovers,  require  insects  with  trunks  of 
some  length,  because  their  nectar  is  so  deeply  hidden 
that  none  but  these  can  reach  it.  And  insects  do  not 
visit  flowers  where  there  is  nothing  to  be  gained. 

Composite  flowers,  such  as  the  daisy,  dandelion, 
camomile,  groundsel,  and  many  others  whose  blossoms 
grow  together  in  flat  heads,  are  easily  fertilized  by 
almost  any  insects ;  and  what  with  this  advantage  and 
the  further  one,  that  so  many  of  the  family  have  downy 
seeds  easily  carried  by  the  wind,  composites  are  among 
the  most  thriving  and  successful  emigrants. 


XX. 

FRIENDS  AND  FOES 

FROM  one  point  of  view  all  animals,  with  the  exception 
of  a  few  insects,  may  be  looked  upon  as  enemies  of  the 
plant-world,  since  they  either  themselves  feed  upon 
plants,  or  live  on  others  who  do.  But  this  would  be  a 
very  partial  view  of  the  matter,  even  where  the  de- 
struction is  complete ;  for  it  is  a  positive  benefit  to  the 
race  that  the  greater  number  of  seedlings,  as  well  as 
seeds,  should  be  devoured,  or  otherwise  removed,  since 
without  this  thinning  of  their  numbers  none  could 
come  to  perfection. 

Linnaeus  calculated  that  any  one  annual  which  pro- 
duced but  two  perfect  seeds — its  descendants  doing 
the  same  every  year — would  have  increased  to  a  million 
in  the  course  of  twenty  years.  Now  all  annuals  do 
considerably  more  than  this  as  a  rule ;  and  as  they  do 
not  increase  at  an  alarming  rate,  it  is  evident  that  their 
existence  must  in  many  instances  be  cut  short,  at  one 
time  or  other  of  their  career. 

Plants  have  many  and  various  enemies  which  attack 
them  at  different  stages  of  their  lives,  but  it  is  chiefly 
while  they  are  seedlings  that  they  are  altogether  ex- 
terminated, and  this  they  are  wholesale.  Out  of  357 
seedling-weeds  growing  together  without  any  crowding 


Friends  and  Foes  301 

in  a  small  plot  of  ground,  Mr.  Darwin  found  that  295 
were  destroyed,  mainly  by  slugs  and  insects. 

From  the  point  of  view  of  the  destroyed — the  victims 
— these  creatures  were  undoubtedly  foes ;  but  from  that 
of  the  survivors  they  were  as  certainly  friends,  for  the 
latter  would  grow  up  all  the  more  vigorous  for  having 
plenty  of  space. 

But  if  slugs  and  insects  were  allowed  to  multiply 
without  check,  they  would  become  foes  and  nothing 
else,  and  would  end  by  eating  up  every  green  thing. 
There  are  checks  upon  their  increase,  however;  and 
besides  this,  many  plants  are  to  some  extent  protected 
against  them,  as  otherwise  certain  species  might  be 
exterminated  altogether. 

Plants  like  the  grasses,  which  bear  vast  quantities  of 
seed,  are  protected  by  their  very  numbers,  and  can 
well  afford  to  be  eaten,  if  but  a  small  proportion  be 
allowed  to  perfect  and  disperse  their  seed ;  but  others, 
less  prolific,  are  guarded  in  various  ways,  being  made 
either  disagreeable  or  difficult  of  approach. 

The  whole  of  the  Gentian  order,  for  example,  are  so 
extremely  bitter,  that  they  are  seldom  touched  even 
by  caterpillars;  and  the  Eschscholtzia,  which  is  of 
another  order,  is  also  so  intensely  bitter  as  to  be  more 
avoided  by  slugs  and  the  like  than  any  other  plant,  it 
is  said.  Even  Eschscholtzias  are,  however,  a  good 
deal  bitten  at  times,  probably  by  earwigs,  but  this  may 
be  owing  to  drought  and  consequent  scarcity  of  vege- 
table matter,  as  it  is  not  a  common  occurrence.  It  is 
at  least  something  to  be  proof  against  certain  classes 
of  enemies;  and  no  plants  are  defended  against  all, 
since  they  are  intended  to  be  eaten,  though  not 
exterminated. 


302  Friends  and  Foes 

The  bark  of  oaks,  elms  and  willows,  is  made  suffi- 
ciently unpleasant  to  most  animals  by  the  presence  of 
tannin ;  and  ferns  contain  so  much  of  this  that  few 
animals  care  to  eat  them,  though  they  have  their  own 
particular  caterpillars. 

Many  plants  are  not  merely  disagreeable,  but  even 
poisonous  to  mammals,  though  birds  may  eat  the  seeds, 
and  insects  the  leaves,  with  impunity;  and  others  again 
are  of  such  a  biting  flavour  as  to  raise  blisters  on  the 
tongue  or  skin.  Some  members  of  the  buttercup 
family  are  of  this  acrid  nature,  and  the  buttercup  itself 
is  said  to  be  avoided  by  cattle ;  but  on  the  other  hand, 
the  deadly  nightshade,  which  is  fatal  to  man,  is  eaten 
with  impunity  by  the  rabbit. 

The  Asclepias  gigantea  of  the  desert  is  so  deadly 
that  the  least  drop  of  the  poisonous  milk  contained  in 
its  leaves  and  stem  causes  total  blindness  if  it  touches 
the  eye;  and  even  those  who  cut  the  plant  for  fire- 
wood must  beware  of  so  much  as  touching  their  eyes 
afterwards,  since  a  merely  accidental  rub  may  deprive 
them  of  sight. 

One  would  suppose,  therefore,  that  the  asclepias 
was  so  amply  protected  as  to  have  no  enemy  at  all ; 
yet  there  is  one  upon  which  its  deadliness  makes  no 
impression  whatever;  and  this,  the  goat,  devours  it 
greedily,  though  all  other  animals  refuse  and  avoid  it. 

Goats  are  indeed  the  most  omnivorous  and  most 
destructive  of  animals,  and  very  few  plants,  or  even 
trees,  are  safe  from  them.  Neither  the  thorns  of  the 
prickly  pear,  nor  the  flinty  '  needles '  of  young  pines 
and  firs  afford  any  sufficient  protection  against  them ; 
and  yet  even  the  goat  has  its  preferences,  and  is  said 
to  refuse  lettuce,  while  it  will  eat  cabbage. 


Friends  and  Foes  303 

Probably  each  plant  has  its  own  appropriate  enemy 
— really  a  friend  to  the  race — whose  office  it  is  to  check 
its  undue  multiplication.  And  one  reason  why  plants 
introduced  into  other  lands  sometimes  run  riot  there, 
and  even  extirpate  the  natives,  is  just  this,  that  they 
are  foreigners,  and  that  there  is  at  first  no  animal  to 
keep  them  within  bounds.  If  there  had  been  some 
common  bird  to  eat  the  seeds  of  the  wild  artichoke  or 
*  thistle,'  for  instance,  when  first  it  reached  South 
America,  it  could  not  have  gained  the  upper  hand  so 
entirely  as  it  has  done.  At  present  the  plant  itself  is 
eaten  to  some  extent  by  horses  and  mules,  but  only 
when  other  forage  is  scarce,  as  its  spiny  leaves  are  a 
great  protection,  and  make  it  actually  formidable  to 
most  quadrupeds.  Goats  might  manage  it,  but  other- 
wise it  seems  that  birds  are  what  are  wanted  to  keep 
it  in  check.  Eventually,  however,  man  may  prove  to 
be  its  '  appropriate  enemy,'  and  will  cut  and  stack  it, 
as  he  has  begun  to  do  with  its  cousin  the  Scotch  thistle 
in  Victoria,  which  proves  excellent  winter  food  for 
cows,  when  thus  treated,  as  the  spines  lose  their  stiff- 
ness when  dried. 

Foreign  plants  are,  however,  sometimes  at  a  dis- 
advantage when  introduced  into  a  new  country,  as 
they  may  meet  with  enemies  unknown  in  their  native 
land,  and  against  which,  therefore,  they  are  un- 
defended. But  generally  speaking,  foreigners  arc 
much  let  alone  at  first,  for  most  animals  are  sus 
picious  of  anything  new  and  unfamiliar;  and  nearly 
all,  especially  of  the  mammalia,  far  surpass  us  in 
keenness  of  scent.  They  'live  in  a  world  of  odours,' 
most  of  them  with  their  noses  near  the  ground,  always 
on  the  qui  vive  to  notice  anything  strange ;  and  gener- 


304  Friends  and  Foes 

ally  speaking,  what  is  new  and  strange  that  they 
mistrust  and  avoid. 

This  fact  was  strikingly  illustrated  on  one  occasion 
by  a  bear  in  the  Jardin  des  Plantes,  one  of  certain 
victims  whom  it  was  found  necessary  to  despatch.  A 
bun  dipped  in  prussic  acid  was  offered  to  this  bear, 
and  was  graciously  accepted ;  but  Bruin  quickly 
decided  that  there  was  something  not  quite  satis- 
factory about  it.  He  was  familiar  with  buns,  but  this 
was  not  an  ordinary  bun,  and  therefore  might  be  mis- 
chievous, so  he  dropped  it  into  the  water  and  prudently 
allowed  it  to  soak  until  the  strange  smell  was 
gone. 

In  a  similar  way,  cattle  imported  and  turned  out  to 
feed  in  strange  pastures  are  said  usually  to  avoid 
poisonous  plants,  not  because  they  are  poisonous,  but 
because  they  are  strange,  and  therefore  to  be  doubted. 

When  they  have  attained  a  fair  size  most  plants  can 
well  afford  to  have  some  of  their  leaves  eaten ;  but  if 
no  blossoms  are  left  the  plant  dies  without  successors, 
and  this,  in  many  cases  at  least,  is  not  to  be  desired. 
Accordingly  we  find  that,  as  a  rule,  blossoms  are 
avoided  by  all  animals,  including  even  caterpillars, 
which  would  rather  die  of  hunger  than  eat  the  blossom 
of  the  very  plant  whose  leaves  are  their  favourite  food. 
Earwigs,  indeed,  are  less  particular,  and  are  given  to 
biting  dahlias;  and  whatever  wild  rabbits  may  do, 
tame  ones  often  begin  with  the  blossom  of  poppies  and 
succory,  as  if  it  were  a  choice  morsel. 

Plants  are  protected  against  indiscriminate  con- 
sumption in  a  variety  of  ways:  by  being  unpleasant 
in  flavour  or  poisonous,  by  the  toughness  and  hardness 
of  their  foliage,  by  prickles  and  by  thorns,  sometimes 


Friends  and  Foes  305 

of  formidable  size,  and  by  hairs,  whether  sticky  or 
stinging. 

Certain  caterpillars  are  proof  against  the  stings  of 
the  nettle  ;  but  as  a  rule  this  plant  is  very  carefully  let 
alone ;  and  such  grasses  and  sedges  as  are  unpleasantly 
wiry  are  also  avoided  by  cattle,  unless  they  are  driven 
to  eat  them  by  hunger.  The  Alpine  fescue-grass  is  so 
extremely  stiff  that  its  needle-like  points  prick  the 
noses  of  unwary  animals,  and  no  doubt  in  this  way  it 
escapes  being  eaten ;  but,  on  the  other  hand,  it  is  ex- 
terminated wholesale  by  the  herdsmen  of  the  Alps, 
who  burn  it  where  it  occurs  in  large  quantities.  In 
the  ordinary  course  of  nature,  however,  where  man 
does  not  interfere,  it  is  no  doubt  very  effectually  pro- 
tected. 

Prickles  and  thorns  are  among  the  most  efficient 
guards  a  plant  can  have,  and  are  often  positively  for- 
midable weapons  of  defence.  One  has  only  to  think 
of  the  strong,  stout  thorns  of  the  rose,  and  the  long, 
sharp  ones  of  the  gooseberry-bush  to  realize  that  it 
would  be  dangerous  for  any  animal  to  attempt  to  make 
a  meal  of  them.  The  sharp  little  prickles  of  the  rasp- 
berry, too,  must  make  it,  one  would  think,  anything 
but  pleasant  eating  to  most  creatures,  though  donkeys 
will  munch  raspberry-canes  as  well  as  thistles. 

But  all  these  small  thorns,  sharply  as  they  can 
wound,  are  a  mere  trifle  compared  with  those  which 
protect  many  foreign  plants  and  trees  until  they  have 
grown  beyond  the  reach  of  cattle.  There  is  a  palm, 
for  instance,  in  Ceylon,  whose  trunk  is  covered  for  the 
first  six  or  eight  feet  with  a  coating  of  thorns  so  closely 
set  together  that  the  bark  is  hardly  visible ;  and  there 
is  also  a  climbing  plant,  very  common  in  the  jungles, 

20 


306  Friends  and  Foes 

which  is  thickly  studded  with  knobs,  each  ending  in  a 
thorn  as  large  and  sharp  as  the  bill  of  a  sparrow-hawk. 
Even  the  tough  hide  of  the  elephant  is  not  proof 
against  the  'jungle  nail/  or  '  elephant  thorn/  an  acacia, 
whose  lancet-like  spines — which  frequently  grow,  not 
singly,  but  in  branching  clusters — make  any  forest 
where  it  abounds  absolutely  impassable. 

The  buffalo  thorn,  or  bull's  horn  acacia,  is  interest- 
ing in  another  way.  Its  trunk  and  branches  are  beset 
by  strong  thorns  two  or  three  inches  long  and  as  sharp 
as  needles,  which  grow  in  pairs,  and  are  shaped  just 
like  horns.  But,  as  if  this  were  not  enough  to  ensure 
its  safety,  the  tree  maintains  as  well  a  standing  army, 
which  keeps  off  all  aggressors,  large  and  small,  at 
least  during  the  wet  season,  for  then  every  thorn  is 
tenanted  by  ants,  which  rush  out  and  sting  severely 
any  animal  venturing  to  touch  the  tree. 

Caterpillars,  which  might  make  their  way  between 
the  thorns  without  injury,  have  no  chance  against  the 
ants,  and  even  their  own  rapacious  relations,  the  leaf- 
cutting  ants,  are  completely  barfled. 

The  ants  of  the  buffalo  thorn  are  not  to  be  found 
in  the  forest,  or,  indeed,  anywhere  except  on  this  par- 
ticular  acacia,  which  belongs  especially  to  the  dry 
plains  or  savannahs  of  Central  America.  When  the 
'  horns '  are  first  put  forth  they  are  filled  with  a  soft, 
sweetish  pulp,  which  the  ants  hollow  out,  burrowing 
between  the  partition  which  separates  them,  and  thus 
making  a  single  dwelling  of  each  pair.  The  thorns  do 
not  suffer  in  any  way  from  this  treatment,  and  continue 
to  grow  until  they  have  reached  their  full  size. 

But  the  ants  do  not  frequent  the  trees  for  the  sake 
of  comfortable  lodgings  merely.  They  want,  and  find, 


Friends  and  Foes  307 

food  as  well.  At  the  base  of  each  pair  of  young 
leaflets  there  is  a  gland,  which  contains  a  liquid  some- 
thing like  honey ;  and,  besides  this,  the  young  leaves 
bear  what  are  described  as  'minute  golden  pears,' 
small,  sweet  protuberances,  which  ripen  in  succession 
and  need  constant  examination.  These  two  delicacies, 
their  sole  food,  the  ants  are  always  ready  to  defend, 
and  during  the  wet  season  hundreds  of  them  may  be 
seen  running  about  on  the  young  leaves,  which  are 
thus  kept  clear  of  all  enemies  for  some  time  after  they 
unfold. 

Many  other  plants  (among  them  being  many  orchids 
and  passion  flowers)  are  similarly  defended  in  the 
tropics  of  both  east  and  west,  the  ants  rushing  out 
and  biting  the  finger  of  anyone  touching  them  ;  and 
though  they  have  their  disadvantages,  when,  as  in  the 
case  of  the  trumpet-tree,  they  choose  to  keep  '  cows  ' 
— scale  insects  which  suck  the  juices  of  the  hollow 
stem  within  which  they  live — still,  it  is  evident  that  in 
other  instances  their  guardianship  is  not  only  valuable, 
but  positively  necessary.  This  was  clearly  proved  in 
the  case  of  some  acacias  raised  in  a  garden  in  St. 
Domingo,  Nicaragua,  which  were  cut  to  pieces  by  the 
parasol  ant  simply  for  lack  of  their  natural  defenders. 
For  St.  Domingo  is  situated  in  the  midst  of  forests, 
and  the  ants  which  protect  the  acacia  are  never  found 
within  their  precincts,  or,  indeed,  anywhere  but  on  the 
savannahs. 

This  parasol,  or  leaf-cutting  ant,  is  one  of  the  worst 
enemies  of  vegetation  in  tropical  America,  where  it  is 
called  the  curse  of  the  country,  owing  to  the  damage 
which  it  inflicts  on  the  crops.  It  may  be  a  friend  in 
disguise  to  the  wild  crops,  by  preventing  their  too 


308  Friends  and  Foes 

great  increase,  and  its  services  in  the  past  in  burrow- 
ing and  tunnelling  and  in  adding  to  the  organic  matter 
of  the  soil  must  not  be  forgotten ;  but  at  the  present 
day  the  farmer  can  hardly  look  upon  it  as  other  than 
an  enemy.  It  is  the  cultivated  plants  of  foreign  origin 
which  it  especially  attacks,  for  very  many  of  the  natives 
are  protected  against  it  in  one  way  or  other,  while  the 
foreigners  are  undefended — a  good  example  of  the 
risks  sometimes  run  in  this  way  by  colonists. 

The  Indians  defend  their  trees  by  a  very  simple 
device,  that  of  fastening  thick  wisps  of  grass  with  the 
sharp  points  turned  downwards  round  their  stems. 
The  multitude  of  points  quite,  baffles  the  ants,  and 
prevents  their  climbing  further  up.  Orange-growers 
plant  their  young  trees  in  the  centre  of  ring-shaped 
earthen  vessels,  which  are  kept  rilled  with  water,  and 
answer  one  of  the  purposes  of  the  natural  '  basins '  of 
the  teasel  and  other  similar  plants. 

In  some  parts  of  America  orange-trees  have  run 
wild,  and  have  formed  thickets,  in  spite  of  the  ants ; 
but,  generally  speaking,  all  the  species  of  the  citron 
family — the  orange,  lemon,  etc.  —  except  the  lime, 
would  be  very  quickly  destroyed  if  they  were  left 
without  the  help  and  protection  of  man.  The  lime 
has  run  wild,  and  seems  to  be  less  liked  by  the  ants 
than  the^  orange  and  lemon,  whose  leaves  they  '  cut  up 
into  sixpences  '  when  they  have  the  opportunity,  leaving 
nothing  but  rags  behind  them.  They  are  terrible 
enemies  to  young  plantations,  nurseries,  and  gardens ; 
but  they  greatly  fear  the  small  ants  which  protect 
certain  plants. 

The  agricultural  ant  of  Texas  occupies  a  different 
position  from  that  of  the  leaf-cutter,  for  she  is  really 


Friends  and  Foes  309 

an  agriculturist  on  her  own  account,  and  the  only  one 
in  the  animal  world,  so  far  as  we  know.  She  is  no 
more  an  enemy  to  vegetation,  therefore,  than  the 
farmer  who  cuts  down  '  bush '  that  he  may  grow 
wheat,  for  she  does  a  precisely  similar  thing. 

It  is  unfortunate  for  the  farmer,  of  course,  when  her 
'  bush '  chances  to  be  his  corn  or  sweet  potatoes, 
which  she  cuts  down  as  ruthlessly  as  he  does  scrub ; 
or  when  she  decides  that  his  young  fruit-trees  must  be 
stripped  of  their  leaves  because  they  keep  off  too  much 
of  the  sunshine  from  her  domain.  But  she  does  not 
plunder  his  crops  for  food,  and  she  does  grow  and  tend 
and  reap  crops  of  her  own  as  regularly  and  carefully  as 
he  does  himself. 

For  -this  purpose,  at  least  partly,  she  makes  circular 
clearings  some  ten  or  twelve  feet  in  diameter,  some- 
times in  rough,  wild  pasture,  sometimes  in  the  middle 
of  the  farmer's  fields;  and  she  clears  away  his  cotton, 
or  corn,  just  as  impartially  as  she  does  the  weeds,  for 
to  her  they  are  weeds.  Considering  her  size,  her 
labours  are  truly  herculean,  for  she  cuts  through,  with 
her  teeth,  stems  as  thick  as  a  thumb ;  and  by  dint  of 
sawing,  twisting,  pulling,  biting,  she  clears  everything 
away,  no  matter  how  rank  the  growth.  And  this  is 
not  all,  for  the  space  is  not  only  cleared  once,  but  kept 
clear  till  the  'ant-corn'  has  ripened — a  matter  in- 
volving no  small  labour  where  it  is  surrounded  by  a 
dense  growth  of  weeds  always  ready  to  encroach. 

The  crop  consists  of  a  tall,  yellowish  grass,  and  not 
so  much  as  a  blade  of  any  other  species  is  allowed 
among  it.  It  ripens  about  the  end  of  June,  when  the 
seed  is  cut  from  the  stalk  and  carefully  stored.  That 
which  falls  of  itself  to  the  ground  is  not  harvested,  and 


310  Friends  and  Foes 

it  is  probably  from  this  that  the  next  year's  crop 
springs,  though  some  have  declared  that  the  ants 
actually  sow  as  well  as  reap.  Harvest  over,  the  dry 
stubble  is  cut  and  cleared  away,  and  weeds  are  left  to 
grow  as  they  will  during  winter,  the  work  of  cutting 
them  down  beginning  vigorously  again  in  spring. 

These  ants  live  chiefly  on  grass  seeds,  which  they 
gather  from  a  distance  as  well  as  from  the  home  crop ; 
but  though  they  do  not  steal  food  from  the  farmer, 
they  inflict  much  injury  on  his  fields,  and  destroy  many 
an  acre  of  produce,  no  amount  of  ploughing  being  suf- 
ficient to  drive  them  away. 

It  is  impossible  even  to  enumerate  the  many  animals 
which  feed  upon  plants,  and,  when  allowed  to  increase 
unduly,  become  the  enemies  instead  of  the  friends  of 
vegetation,  not  merely  checking  overcrowding,  but 
destroying  wholesale. 

We  cannot  attempt  any  description  of  the  devasta- 
tions caused  by  locusts,  one  of  whom  is  reported  by 
Mahomet  to  have  remarked,  *  We  are  the  army  of  the 
great  God ;  we  produce  ninety-nine  eggs.  If  the 
hundred  were  complete,  we  should  consume  the  whole 
earth  and  all  that  is  in  it.'  Nor  can  we  tell  of  the 
ravages  of  the  American  crickets,  which  eat  up  a  whole 
crop  of  maize  in  a  night ;  or  of  the  caterpillars,  which 
would  completely  destroy  the  tobacco  plantations  if 
not  constantly  picked  off  leaf  by  leaf;  or  of  the  minute 
beetles,  whose  grubs,  penetrating  between  wood  and 
bark,  destroyed  in  1780  and  the  following  years  a 
million  fir-trees  in  the  Harz  mountains  and  Switzer- 
land, 50,000  trees,  chiefly  oaks,  more  recently  in  the 
Bois  de  Vincennes,  and  are  causing  avenues  of  fine 
elms  to  disappear  in  the  north  of  France.  Green  fly, 


Friends  and  Foes  311 

scale  insects,  slugs,  wireworm,  grubs,  and  the  various 
other  plagues  known  to  the  gardener  and  agriculturist 
must  also  be  passed  over,  and  we  must  go  on  to 
consider  by  what  natural  means  these  various  creatures 
are  kept  in  check  and  prevented  from  becoming  positive 
enemies  to  all  vegetation,  instead  of  merely  thinning 
the  ranks,  to  the  advantage  of  the  survivors. 

For,  when  one  reads  of  flights  of  butterflies  which 
take  days  and  weeks  to  pass,  of  armies  of  caterpillars 
which  stop  the  progress  of  railway  trains,  and  of 
dense  clouds  of  locusts  several  miles  long,  it  is  quite 
evident  that  unless  their  increase  were  restricted  by 
some  very  efficient  means  they  would  all  more  than 
justify  the  locust's  boast,  and  leave  not  so  much  as  a 
blade  of  grass. 

Man  is  utterly  unable  to  cope  with  them  by  any 
means  at  his  present  disposal,  and  when  he  interferes 
with  nature's  way  of  keeping  them  within  bounds,  he 
learns  by  hard  experience  his  own  utter  helplessness, 
and  often  not  till  then. 

In  the  Middle  Ages  people  seem  to  have  had  the 
feeling  that  they  ought  to  be  able  to  control  grubs  and 
the  like,  by  the  mere  word  of  command,  and  the 
chroniclers  of  the  time  often  give  reports  of  the  law- 
suits instituted  against  these  creatures.  In  1479,  for 
example,  the  canton  of  Berne  was  troubled  with  such 
an  overwhelming  plague  of  grubs  that  the  Council 
petitioned  the  Archbishop  of  Lausanne  to  banish  them, 
and  the  priests  were  authorized  by  him  to  do  so.  In 
accordance  with  the  usual  custom  on  these  occasions, 
advocates  were  appointed  for  both  parties — the  grubs 
and  the  people.  A  written  summons  was  issued  ;  the 
grubs  were  cited  to  appear,  and  some  were  brought 


312  Friends  and  Foes 

into  court ;  but  they  were  not  fairly  treated,  as  the 
advocate  assigned  to  them  was  no  longer  living,  and 
judgment  was  given  against  them  in  these  terms : 
'  We,  the  Archbishop  of  Lausanne,  condemn  and  ex- 
communicate ye  obnoxious  worms  and  grubs,  that 
nothing  shall  be  left  of  ye  except  such  parts  as  can  be 
useful  to  man.' 

No  steps  seem  to  have  been  taken,  however,  to  give 
effect  to  the  sentence,  and  the  grubs  obstinately 
ignored  it. 

But  if  the  Council  could  have  imported  a  few 
hundreds  of  small  birds,  they  would  most  likely  have 
been  quickly  rid  of  the  plague ;  for  these,  and  these 
alone,  are  the  natural  and  most  effectual  provision  for 
keeping  the  numbers  of  grubs,  caterpillars,  and  the 
like  within  their  proper  limits. 


XXI. 


*  IF  nature's  militia,  the  army  of  birds,  be  killed,  it  will 
be  impossible  to  find  a  substitute  for  their  faithful 
guardianship.' 

*  Birds  are  nature's  soldiers,  and  keep  in  subjection 
the  inferior  animals.  Their  other  uses  are  scarcely 
worthy  of  notice  compared  with  their  labours  in  the 
destruction  of  insects.' 

Wise  words,  which  cannot  be  too  often  insisted  on ; 
for  though  we  are  beginning  to  wake  up  to  the  immense 
value  of  the  feathered  tribes  as  guardians  of  our  fields, 
we  are  still  only  beginning ;  and,  unfortunately,  farmers 
and  gardeners,  the  very  persons  most  interested,  are 
precisely  those  whom  it  is  most  difficult  to  arouse. 

They  know  well  enough,  of  course,  that  insects, 
generally  speaking,  are  their  enemies ;  but  they  do  not 
yet  recognise,  as  they  ought,  that  the  birds  are  their 
friends,  who,  if  only  let  alone,  would  save  the  crops 
from  these  marauders. 

A  plague  of  grubs  finds  us,  in  fact,  just  as  helpless  as 
our  forefathers  in  the  Middle  Ages,  and  almost  more 
hopeless,  for  we  no  longer  believe  in  trying  to  *  banish ' 
our  enemies,  and  we  have  not  yet  discovered  any  more 


314  Nature's  Militia 

effectual  means  of  dealing  with  them.  When  the  in- 
fliction comes,  we  talk  mysteriously  of  *  blight '  and 
*  weather ';  and  it  seldom  occurs  to  us  to  connect  the 
increase  of  grubs  with  the  destruction  of  birds,  even 
though  we  must  know,  as  a  matter  of  fact,  that  the 
latter  live  mainly  upon  the  former,  and  that  therefore 
for  every  bird  killed,  so  many  grubs  must  be  left 
alive. 

However,  as  before  said,  we  are  beginning  to  wake 
up,  and  in  some  cases  the  awakening  has  been  so  rude 
that  further  slumbers  are  almost  impossible. 

It  is  now  some  thirty  years  since  piteous  complaints 
were  rife  in  Germany  and  Switzerland  of  the  alarming 
increase  in  the  number  of  destructive  insects,  which 
made  their  appearance  in  overwhelming  swarms,  and 
inflicted  the  greatest  injury  on  the  fields.  And  at  last 
it  occurred  to  the  authorities  that  insects  had  multiplied 
because  birds  had  to  so  large  an  extent  vanished.  The 
'  militia '  had,  in  fact,  been  either  killed  off  or  driven 
away ;  they  had  been  destroyed  in  the  most  insane 
manner,  in  ignorance  and  sheer  wantonness ;  and  also 
they  had  been  '  improved  '  away  by  the  spread  of  agri- 
culture. In  whatsoever  way  it  had  come  to  pass,  the 
result  was  the  same — there  were  fewer  birds,  there 
were  more  grubs ;  and  as  the  latter  increase  much 
more  rapidly  than  the  former,  the  prospect  was  a 
dismal  one.  The  land  was  being  devoured. 

And  it  was  devoured,  partly  at  least,  because  more 
had  been  taken  into  cultivation.  For  woods  and 
thickets  and  groups  of  trees  had  been  cut  down  to 
make  way  for  fields ;  and  land  being  precious,  hedges 
were  considered  an  unnecessary  extravagance.  There 
are,  of  course,  still  extensive  woods  and  forests  in 


Nature's  Militia  315 

Germany,  but  one  may  travel  many  a  long  mile  without 
seeing  any  of  the  hedgerows  with  which  he  is  familiar 
in  England.  The  fields  are  for  the  most  part  one  large 
expanse,  without  any  bordering  of  trees  or  bushes. 

But  it  is  quite  possible  to  be  too  thrifty.  If  every 
foot  of  land  is  occupied  by  crops,  where  are  the  birds 
to  build  their  nests  ?  Most  of  them  need  more  shelter 
than  is  to  be  found  upon  the  ground,  and  if  they  cannot 
find  it  in  one  place  they  are  obliged  to  look  for  it  in 
another.  If  the  farmer  will  not  spare  them  a  few  trees 
and  bushes,  they  are  compelled  to  desert  his  fields  and 
leave  them  unprotected. 

But  this  is  not  all.  Grubs,  as  well  as  birds,  find 
shelter  in  the  hedges  ;  and  not  only  shelter,  but  food. 
When  the  birds  are  driven  away,  therefore,  the  grubs 
are  driven  away,  too ;  but,  alas  !  while  the  birds 
migrate  to  a  distance,  the  grubs  are  only  driven  out  of 
the  bushes  and  hedge-plants,  where  they  are  compara- 
tively harmless,  into  fields,  orchards,  and  gardens, 
where,  in  the  absence  of  the  '  militia,'  they  run  riot  as 
they  will. 

We  see,  indeed,  the 

' .  .  .  .  hedges  all  alive 

With  birds  and  gnats,  and  large  white  butterflies, 
Which  look  as  if  the  May-flower  had  caught  life, 
And  palpitated  forth  upon  the  wind.' 

We  see ;  but  perhaps  we  hardly  realize  that  if  the 
hedge  be  cut  down  its  population  will  find  quarters 
elsewhere ;  and  that  while  the  birds  betake  themselves 
to  the  nearest  thicket,  perhaps  some  distance  off,  the 
butterflies  and  moths  will  simply  flit  a  few  yards,  many 
of  them  being  quite  content  to  supply  their  offspring 
with  cultivated  plants  when  they  cannot  get  wild  ones. 
Somewhere  or  other  they  must  and  will  lay  their  eggs 


316  Natures  Militia 

— if  not  in  the  hedgerow,  then  in  the  garden  ;  and  the 
grub  of  the  white  butterfly  is,  as  we  all  know,  able  to 
make  quite  a  decent  living  upon  cabbage-leaves. 

That  there  should  be  trees  and  bushes,  with  their 
usual  undergrowth  of  wild  plants,  in  the  neighbourhood 
of  cultivated  land  is  therefore  a  double  advantage  :  the 
grubs  are  supplied  with  food,  and  kept  away  from  the 
crops ;  and  the  birds,  the  grubs'  natural  enemies,  are 
attracted,  and  keep  down  their  numbers. 

But  the  larger  the  area  of  land  cultivated,  the  smaller 
the  space  left  to  nature ;  the  more  fields,  the  fewer 
thickets ;  the  fewer  wild  crops  to  feed  the  grubs,  the 
fewer  nesting-places  for  the  birds.  And  thus  the  mere 
fact  that  more  land  had  been  taken  into  cultivation 
would  alone  be  enough  to  account,  in  some  degree,  for 
the  marked  increase  in  the  numbers  of  Germany's 
insect  enemies. 

But  this  was  not  all,  or  nearly  all.  Not  only  had  the 
grubs  been  driven  into  the  fields,  and  the  birds  driven 
out  of  them,  but  the  latter  had  been  killed  wholesale. 
Government  keepers  were  actually  under  orders  to 
destroy  the  woodpeckers,  whose  special  office  it  is  to 
rid  the  trees  of  beetle- grubs,  and  the  cuckoos,  which 
devour  the  hairy  caterpillars  which  no  other  birds  will 
touch,  and  so  on. 

And  the  Germans  have  not  been  the  only,  or  even 
the  chief,  offenders.  They  have  killed  their  own  birds, 
and  have  suffered  for  it.  But  the  Italians  have  done 
worse  ;  for  they  have  waged  deadly  war  upon  the  birds 
which  are  the  common  property  of  Europe.  They  have 
a  perfect  mania  for  slaughtering  small,  insect-eating 
birds,  and  unhappily  they  have  special  opportunities  of 
gratifying  it,  as  large  flocks  of  migrants  pass  through 


Nature's  Militia  317 

this,  to  them  inhospitable  land,  every  year  on  their 
way  to  and  from  the  south.  Considering  the  way  in 
which  they  were  received,  one  wonders  why  they  did 
not  choose  some  other  route ;  but  the  force  of  habit 
seems  to  be  too  strong  for  them,  and  their  ranks  have 
been  thinned  year  after  year  in  the  most  fatal  manner. 
Not  even  the  swallows  were  allowed  to  pass  un- 
molested ;  for  to  catch  them,  by  floating  hooks  baited 
with  flies  in  the  air,  seems  to  have  been  considered  a 
particularly  fascinating  pastime. 

For  months  the  chief  delight  of  the  population  was 
in  catching  birds,  and  several  million  were  killed  regu- 
larly each  autumn  in  the  neighbourhood  of  Verona 
alone.  Larks  are  among  the  most  useful  of  the 
insect-eating  birds,  and  so  entirely  harmless  that 
even  the  farmer  has  no  fault  to  find  with  them.  Yet 
neither  their  usefulness  nor  their  harmlessness  were 
sufficient  to  save  them  from  persecution.  Unluckily 
for  themselves,  and  we  may  add,  for  Europe,  they  had 
chosen  Sicily  as  one  of  the  places  at  which  to  break 
their  journey,  and  they  could  hardly  have  done  worse. 
The  Sicilians  knew  when  to  expect  them,  for  they 
came  regularly  every  autumn,  nearly  a  million  arriving 
daily  for  ten  days,  and  they  gave  them  a  warm  recep- 
tion. Hundreds  of  the  population  went  out  to  meet 
them,  armed  with  guns,  and  there  was  a  regular 
battue.  How  many  were  slain  history  does  not  say, 
but  the  numbers  must  have  been  very  great.  They 
did  not  die  unavenged,  however ;  for  every  lark  killed 
left  so  many  more  insects  to  ravage  the  crops ;  and 
when  people  woke  up  enough  to  put  two  and  two 
together,  and  to  connect  the  plagues  of  insects  with 
the  destruction  of  the  'militia'  which  should  have 


318  Nature's  Militia 

kept  them  under,  measures  were  taken  to  check  the 
persecution. 

To  some  extent  birds  are  now  protected  in  Europe  ; 
but  we  do  not  seem  to  have  learnt  our  lesson  even  yet, 
for  a  cry  that  the  birds  are  being  exterminated  is  now 
making  itself  heard  in  Asia,  Africa,  and  America.  The 
war  carried  on  against  them  in  India,  is  already  having 
very  serious  results  ;  the  swamps  and  marshes  of 
Florida  are  being  depopulated  ;  Guinea  is  being  de- 
spoiled of  its  birds  of  paradise,  and  birds  of  bright 
plumage  are  becoming  more  and  more  rare  everywhere 
all  over  the  world. 

And  why  all  this  slaughter?  Not  because  there  is  a 
famine  in  the  land,  and  the  birds  are  needed  for  food  ; 
not  even  for  the  sake  of  '  sport ' ;  but  because  the 
fashionable  ladies  of  Paris,  London,  and  Vienna  re- 
quire the  sacrifice  of  at  least  thirty  million  birds  every 
year,  that  they  may  decorate  themselves  with  feathers. 

In  India,  which  furnishes  hundreds  of  thousands  of 
skins  every  year,  insect  life  is  rampant  beyond  any- 
thing that  we  have  experience  of,  and  is  *  only  kept 
within  bounds  by  the  utmost  effort  of  all  the  checks 
provided  by  nature.'  The  '  patient,  unpaid  labour  of 
the  useful  small  birds '  is  the  one  only  remedy  for  the 
insect  epidemics  to  which  the  empire  is  liable,  and  it 
is  sheer  madness  to  allow  them  to  be  killed  off. 

We  must  hope  that  the  'Indian  Wild  Birds'  Protec- 
tion Act '  will  at  least  check  the  slaughter,  for,  if  it  be 
allowed  to  go  on,  it  can  have  but  one  result,  and  the 
birds  will  be  avenged  here,  as  they  have  already  been 
in  Europe.  When  once  they  are  gone,  no  artificial 
substitutes  can  by  any  possibility  make  up  for  them. 
One  may  syringe  the  fruit-trees,  cover  the  gooseberry- 


Natures  Militia  319 

bushes  with  road-dust,  pay  regiments  of  school-children 
to  gather  grubs  by  the  quart,  try  in  fact  all  the  various 
expedients  which  have  ever  been  resorted  to,  and  yet 
find  in  the  end  that  it  is  simply  impossible  to  overtake 
the  damage  caused  by  the  absence  of  the  birds,  with 
their  marvellously  keen  sight  and  extraordinary  appe- 
tites. 

Let  us  consider  for  a  moment  one  single  fact.  Mr. 
Darwin  found  that  scarcely  more  than  a  sixth  part  of 
his  seedlings  survived  the  attacks  of  slugs,  snails,  and 
insects.  But  what  does  this  mean  ?  Only  this,  that 
if  the  numbers  of  the  enemy  had  been  increased  by  so 
much  as  a  sixth,  there  would  have  been  no  seedlings 
left  alive  at  all. 

One  additional  slug  or  caterpillar  to  every  five  would 
positively  have  destroyed  the  whole  crop,  even  in 
England,  where  there  are  many  hedgerows  and  many 
birds,  and  where  insect  life  is  not  anything  like  as 
abundant  as  it  is  in  warmer  latitudes,  such,  for  instance, 
as  certain  parts  of  the  United  States,  where  railway- 
trains  are  from  time  to  time  brought  to  a  standstill 
by  armies  of  caterpillars  or  grasshoppers  a  foot 
deep. 

It  is  difficult  to  realize,  or  even  to  form  a  faint  idea 
of,  the  numbers  of  insects,  or  the  extraordinary  rapidity 
with  which  they  multiply ;  for  the  figures  which  are  so 
easily  quoted  are  '  like  the  distances  of  the  heavenly 
bodies,  too  great  for  comprehension :  nothing  equals 
them  except  the  incredible  appetites  of  the  insect- 
eating  birds.' 

Take,  for  example,  the  common  house-fly,  one  of 
which  is  said  to  have  21,000,000  descendants  in  the 
lourse  of  a  single  summer,  or  would  have,  if  all 


320  Nature's  Militia 

were  allowed  to  live.  That  we  do  not  have  a  yearly 
plague  of  flies  is  due  solely  to  the  vigilance  of  the 
birds. 

Look,  again,  at  the  country  about  Torgau  on  the 
Elbe,  where,  a  few  years  ago,  birds  were  so  scarce  that 
a  large  sum  was  spent  yearly  on  the  destruction  of 
grubs  and  caterpillars,  to  save  the  forest  from  utter 
ruin ;  yet  all  that  human  ingenuity  could  devise  was 
quite  inadequate  ;  800  acres  of  fir  were  entirely 
stripped  one  year,  and  at  the  same  time  so  much 
grass  was  devoured  that  it  was  necessary  to  import 
hay.  In  Hesse,  too,  all  efforts  to  deal  with  a  similar 
plague  of  caterpillars  were  equally  vain ;  and  it  was 
noticed  that  they  were  especially  destructive  where 
there  were  few  trees  to  divert  their  attention  and 
to  attract  the  birds. 

The  shrew-mouse,  hedgehog,  mole,  lizard,  frog,  toad, 
bat,  and  some  of  the  beetles,  are  all  excellent  insect- 
hunters,  and  the  wasp  and  ichneumon- fly  do  good 
work  against  caterpillars.  But  though  their  services 
are  valuable,  the  birds  do  more  than  all  besides,  each 
kind  in  its  own  especial  department.  Some  pick 
insects,  or  their  eggs,  from  the  leaves,  others  from  the 
bark ;  some  dig  them  and  their  chrysalids  from  the 
earth,  others  catch  them  as  they  fly. 

And  what  quantities  they  devour!  for  their  digestion 
is  very  rapid,  and  whereas  human  beings  require  only 
a  few  ounces  of  dry  food  a  day,  they  swallow  a  quan- 
tity which  is  equal  to  their  own  weight.  Think  of  it ! 
— the  weight  of  a  bird  in  insects ;  green  flies,  for 
instance. 

One  redstart,  kept  in  a  room,  has  been  known  to 
eat  600  flies  in  an  hour;  and  one  blackcap  has  cleared 


Nature's  Militia  321 

about  2,000  green -fly  from  the  rose-trees  in  a  green- 
house in  the  course  of  a  few  hours. 

The  titmouse  is  another  most  active  little  bird, 
constantly  engaged  in  the  hunt  for  food,  creeping  into 
rolled-up  leaves,  and  devouring  by  the  thousand  eggs 
which  would  produce  many  more  hairy  caterpillars 
than  the  cuckoos  could  dispose  of.  As  an  example  of 
the  invaluable  services  which  it  renders  in  effecting  a 
clearance  of  these,  we  may  mention  a  garden  whose 
trees  one  year  were  entirely  stripped  by  caterpillars. 
In  the  autumn  millions  of  eggs  were  seen  on  the 
trunks  and  branches,  and  an  attempt  was  made  to 
clear  them  off  at  considerable  expense,  but  was  soon 
given  up  as  hopeless.  It  seems  strange  that  man 
should  have  to  acknowledge  himself  defeated  by  any- 
thing so  fragile  as  a  butterfly,  but  so  it  was.  How- 
ever, the  birds  came  to  the  rescue.  Twenty  pair  of 
titmice,  as  well  as  some  wrens,  came  and  built  in  the 
garden  the  following  spring,  and  that  summer  the 
trees  suffered  much  less.  By  the  year  after,  the  plague 
was  so  thoroughly  under  control  that  they  remained 
in  full  leaf  the  whole  season. 

The  wren,  like  the  titmouse,  is  perpetually  eating, 
and  feeds  her  young  thirty-six  times  in  an  hour ;  the 
cuckoo,  too,  eats  all  day  long,  every  five  minutes  or  so, 
and  devours  about  170  good- sized  caterpillars  in  the 
day ;  and  as  each  of  these  caterpillars,  if  allowed  to 
reach  the  butterfly  state,  might  lay  some  500  eggs, 
every  cuckoo  rids  us  of  a  possible  85,000  odd  cater- 
pillars daily  ! 

And  the  work  goes  on  vigorously  in  winter,  as  well 
as  in  spring  and  in  summer,  for,  with  all  the  vigilance 
of  the  birds,  caterpillars  and  grubs  innumerable  escape 

31 


322  Natures  Militia 

and  pass  into  the  chrysalis  state,  which  they  spend 
—  as  much  of  it  as  they  are  allowed  —  in  cracks 
and  crannies,  in  sheltered  nooks,  on  twigs  and  trunks 
of  trees,  on  palings  and  walls,  and  in  the  ground. 
These  supply  food  to  the  many  insect-eating  birds 
which  do  not  migrate;  and  but  for  the  unceasing 
labours  of  these  stay-at-homes  we  should  be  over- 
run with  insects  in  the  spring,  in  spite  of  all  that  is 
done  in  the  summer ;  for  each  chrysalis  devoured 
saves  us  from  some  hundreds  of  grubs  or  caterpillars 
later  on. 

From  all  this  it  must  be  sufficiently  plain  that  with- 
out the  birds  every  green  thing  would  be  devoured. 
Yet  to  talk  of  the  '  patient,  unpaid  labour '  of  the  birds 
is  a  trifle  absurd,  for  their  '  labour '  is  its  own  reward, 
and  consists  in  picking  up  food  for  themselves  and  their 
families ;  and  it  is  incessant  merely  because  they  and 
their  nestlings  are  always  hungry — a  most  fortunate 
provision  of  nature  ;  for  does  even  the  most  ardent  of 
bird-lovers  flatter  himself  that  they  would  devote  them- 
selves to  clearing  his  trees  of  grubs  if  they  lost  their 
appetites  ? 

If  anyone  needs  proof  of  what  would  certainly  follow 
the  extermination  of  the  birds,  he  need  only  look  at  the 
island  of  Jamaica,  where  they  are  at  present  very  scarce, 
having  been  killed  off,  chiefly  to  adorn  ladies'  bonnets. 
It  must  be  remembered,  too,  that  while  birds  multiply 
only  by  tens,  insects  increase  by  hundreds,  by  thousands, 
and  by  tens  of  thousands,  in  a  single  season,  so  that 
although  the  birds  are  now  protected  in  Jamaica  it  will 
be  long  before  the  loss  is  made  good.  Meantime  they 
are  terribly  avenged ;  for  the  island  suffers  from  a 
disgusting  and  grievous  plague  of  ticks  imported  with 


Natures  Militia  323 

cattle,  which  swann  upon  every  leaf  and  blade  of  grass, 
except  on  the  higher  hills. 

To  make  matters  worse,  too,  the  mongoose  was 
imported  a  few  years  ago,  and,  like  sundry  other 
importations,  has  proved  a  dismal  failure.  The  idea 
was  that  it  would  kill  off  the  rats  which  so  swarmed  in 
the  sugar-plantations  as  to  be  a  great  nuisance  to  the 
planters.  And  the  mongoose  began  well ;  but  when 
its  numbers  had  increased,  as  they  did  enormously,  it 
began  to  vary  its  diet  of  rats  by  eating  the  eggs  of  such 
birds  as  build  on  the  ground,  and  then  it  went  on  to 
eat  the  birds  themselves,  and  even  poultry,  besides 
killing  off  all  the  lizards  and  snakes,  which  were  not 
only  quite  harmless  but  most  useful  as  insect-eaters. 
In  one  way  and  another,  the  ticks  were  thus  delivered 
from  their  natural  enemies,  and  now  have  things  pretty 
much  their  own  way,  and  seem  likely  to  have  for  some 
time  to  come. 

Jamaica  has  given  birds  for  ticks,  and  the  Isle  of 
Bourbon  made  an  almost  worse  exchange,  for  it  gave 
birds  for  grasshoppers.  A  price  was  put  upon  the  heads 
of  the  swallows,  and  they  disappeared;  but  in  their 
stead  came  grasshoppers  in  such  overwhelming  swarms 
that  they  took  entire  possession  of  the  fields  and 
devoured  everything.  And  the  mischief  did  not  stop 
here — there  was  worse  to  follow ;  for  when  the  green 
things  were  destroyed,  the  island  became  a  prey  to 
scorching,  biting  drought.  So  dangerous  is  it  to  inter- 
fere with  the  wise  arrangements  of  nature,  so  utterly 
impossible  for  any  human  contrivances  to  take  their 
place. 

In  sandy  deserts,  birds  are  naturally  almost  wanting, 
for  there  are  few  trees  or  bushes,  and  little  vegetation 


324  Natures  Militia 

of  any  kind,  either  to  give  them  shelter  or  to  need  their 
protection.  But  it  is  here  that  the  very  worst  of  insect- 
plagues  are  hatched.  Locusts  lay  their  eggs  in  the  hot 
sand,  and  there  seems  to  be  no  appropriate  enemy  on 
the  spot  to  reduce  their  numbers.  As  soon  as  they 
take  to  flight,  indeed,  which  they  are  compelled 
to  do  for  the  sake  of  food,  they  are  followed  and  set 
upon  by  flocks  of  birds,  but  their  numbers  are 
then  so  large  that  they  are  masters  of  the  situa- 
tion, and  devastate  any  district  upon  which  they 
settle. 

It  is,  nowever,  only  when  they  come  down  upon 
cultivated  lands  that  we  hear  .of  their  ravages,  and 
since,  as  before  said,  cultivation  in  most  cases  diminishes 
the  number  of  the  trees  and  with  them  of  the  birds,  it 
is  perhaps  a  question  whether,  in  a  state  of  nature,  the 
birds  might  not  even  then  be  fairly  a  match  for  them. 
They  seem  to  be  so,  at  all  events,  in  the  Khivan  oasis 
of  Turkestan;  for  though  the  locusts  arrive  there  in 
clouds,  often  several  miles  long,  they  are  at  once  set 
upon  by  multitudes  of  small  birds.  But  then  Khiva 
abounds  both  in  birds  and  in  planted  groves,  and  its 
inhabitants  apparently  know  better  than  some  Euro- 
peans the  value  of  their  defenders. 

However,  there  are  probably  few  people  in  the  present 
day  who  would  seriously  dispute  the  value  of  such  birds 
as  live  upon  insects  only.  It  is  when  we  come  to  mixed 
feeders,  such  as  the  sparrow  and  the  rook,  that  opinions 
are  divided. 

A  fierce  battle  rages  round  the  sparrow.  He  is 
accused  of  stealing  corn  and  fruit,  and  of  heartlessly 
destroying  crocuses  for  the  sake  of  the  unformed 
seeds.  In  some  districts  he  is  persecuted  without 


Natures  Militia  325 

tnercy  and  leads  the  life  of  an  outlaw.  Sparrow  clubs, 
encouraged  by  the  farmers,  kill  him  by  the  thousand 
and  destroy  his  nests. 

That  he  is  mischievous  no  one  can  deny,  and  that 
he  sometimes  does  serious  damage  must  be  admitted 
even  by  his  warmest  admirers.  But  if  we  cannot  have 
our  crops  without  paying  toll  upon  them,  it  seems 
better  to  share  with  the  sparrow  than  lose  all  to  the 
grub — the  only  choice,  according  to  some,  which  lies 
before  us. 

The  sparrow's  friends,  the  naturalists,  say  that  each 
sparrow  actually  saves  a  bushel  of  corn,  for  he  himself 
lives  for  nine  months  of  the  year  almost  entirely  on 
grubs,  while  his  family  eat  absolutely  nothing  but 
insect  food  as  long  as  they  remain  in  the  nest.  One 
pair  of  sparrows,  it  is  said,  take  4,300  grubs  or  other 
insects  to  their  young  in  the  course  of  a  week ;  and  that 
they  are  the  deadly  enemies  of  the  cockchafers,  which 
have  done  a  million  pounds'  worth  of  damage  to  the 
crops  in  Normandy,  is  evident,  for  the  wing-cases  of 
700  cockchafers  have  been  found  under  a  single  nest. 

Finally,  we  are  told  that  caterpillars  to  the  number 
of  354,375,000,000  are  eaten  by  sparrows  every  year, 
and  that  while  we  see  the  damage  which  the  sparrow 
does  during  three  months  of  the  year,  we  do  not  see 
how  hard  he  works  for  us  during  the  other  nine,  or 
what  far  greater  damage  he  averts  from  us.  We  grudge 
his  wages,  in  fact,  simply  because  we  do  not  under- 
stand how  vast  are  his  services. 

But  a  few  facts  are  worth  many  arguments.  Let  us 
see  what  has  followed  the  expulsion  of  the  sparrow  in 
one  or  two  cases.  Frederick  the  Great  of  Prussia 
waged  war  against  the  sparrow,  and — he  was  defeated, 


326  Natures  Militia 

ignominiously  defeated,  and  he  had  the  good  sense  to 
own  it.  The  king  liked  cherries,  and  the  birds  liked 
them  too  ;  and  he  gave  orders  that  the  sparrows  should 
be  driven  away,  exterminated,  got  rid  of.  And  he  was 
so  well  obeyed,  that  in  two  years'  time  there  was  not  a 
sparrow  left  in  the  neighbourhood.  So  far  he  was  the 
victor,  for  he  had  certainly  vanquished  the  birds  ;  but 
he  had  overreached  himself,  for  instead  of  having  more 
cherries  he  had  none ! 

There  were  no  cherries  at  all  that  year ;  worse  still, 
there  was  no  fruit  of  any  kind,  but  in  its  stead  a  hideous 
crop  of  caterpillars,  which  had  stripped  the  trees  of 
their  leaves.  Other  birds  besides  sparrows,  of  course, 
eat  caterpillars,  but  the  means  used  to  get  rid  of  the 
sparrows  had  frightened  these  others  away  also.  The 
orchards  had  been  deprived  of  their  guardians,  and  the 
enemy  had  taken  possession,  and  before  matters  could 
be  set  right  sparrows  had  to  be  imported,  at  consider- 
able expense;  for  they  would  never,  it  is  said,  have 
returned  of  their  own  accord,  as  they  are  not  given  to 
wandering. 

Take  another  instance.  In  Hungary,  as  elsewhere, 
sparrows  are  given  to  stealing  corn,  and  they  were 
outlawed  in  consequence.  But  in  a  short  time  it  was 
found  that  the  people  were  in  danger  of  perishing  by 
famine,  owing  to  the  frightful  increase  of  insect-plagues. 
The  decree  against  the  sparrows  was  hastily  revoked, 
for  they,  and  they  only,  could  keep  down  the  beetles, 
and  the  thousand  winged  insects  of  the  lowlands. 

Then  again,  in  the  spring  and  early  summer  of  1888, 
there  was  an  almost  unprecedented  attack  of  maggots 
in  the  Kentish  orchards,  and  in  many  cases  the  nut 
and  apple  crops  were  grievously  damaged,  if  not 


Natures  Militia  327 

destroyed.  Vigorous  efforts  were  made  to  fight  the 
enemy,  but  all  was  in  vain,  and  the  terrible  and  unusual 
increase  in  their  numbers  was  ascribed  by  some  of  the 
wiser  farmers  to  the  wholesale  slaughter  of  sparrows. 

Of  course  sparrows,  as  well  as  chaffinches,  bullfinches, 
linnets  and  others,  eat  some  amount  of  grain  (though 
not  necessarily  the  farmer's),  especially  when  insects 
are  scarce  ;  and  sometimes,  no  doubt,  they  take  more 
fruit  than  the  owner  cares  to  spare  them.  Nothing  is 
perfect ;  but  without  the  birds  there  would  be  no  crops 
at  all,  which  would  surely  be  the  greater  evil;  and 
besides  eating  as  much  insect  as  vegetable  food  during 
the  summer,  which  even  the  grain-feeders  do,  it  is  also 
a  fact  that  the  seeds  which  they  chiefly  eat  are  those 
of  wild  plants  producing  such  superabundant  crops, 
that  they  would  overrun  and  choke  other  vegetation,  if 
there  were  not  some  check  to  their  increase.  No  less 
than  321  chickweed  seeds,  for  instance,  were  found  in 
the  crop  of  one  sparrow. 

Other  birds  eat  large  quantities  of  burdock,  plantain, 
groundsel,  and  thistle-seed ;  and  without  their  help  we 
can  see,  from  the  state  of  things  in  Australia,  how 
rampant  and  unmanageable  these  plants,  with  their 
easily-dispersed  seeds,  might  become. 

Pigeons  are  the  only  birds  which  live  on  nothing  but 
vegetable-food ;  yet  the  wood-pigeon  is  now  recognised 
as  such  a  valuable  servant  in  Belgium,  from  its  habit 
of  eating  the  seeds  of  the  poppy,  spurge  and  others, 
which  no  domestic  animal  can  touch,  that  it  is  strictly 
preserved.  Where  such  seeds  are  not  to  be  had  in 
sufficient  quantities,  no  doubt  the  pigeon  makes  up  for 
it  by  stealing  peas  and  corn,  but  the  Belgians  seem  to 
have  made  up  their  minds  that  it  is  better  to  run  the 


328  Natures  Militia 

risk  of  having  to  pay  occasional  toll  to  the  pigeons, 
than  to  have  their  crops  choked  with  weeds. 

In  this  chapter  we  a~e  necessarily  considering 
'nature's  militia'  chiefly  as  they  affect  the  crops  of 
farmer  and  gardener,  for  it  is  here  that  we  are  best  able 
to  see  their  work ;  and  from  what  they  do  in  field  and 
"  orchard,  we  are  able  to  form  some  idea  of  what  their 
work  is  in  the  uncultivated  fields  and  woods  of  the  world. 

It  is  only  when  the  birds  come  into  contact  with 
man  that  any  doubts  as  to  their  usefulness  can  possibly 
arise,  and  even  here,  in  that  part  of  '  the  green  world ' 
which  he  has  taken  into  his  keeping,  we  are  learning 
more  and  more  to  see  that  they  are  not  only  useful, 
but  actually  indispensable. 

With  the  exception  of  the  flying  insects  which  carry 
pollen  from  flower  to  flower,  there  are  few  insects  in 
any  part  of  the  world  which  are  not  the  enemies  of 
those  who  cultivate  the  soil,  though,  like  prairie-fires, 
they  have  their  uses  where  nature  is  sole  farmer,  and 
it  would  be  rash  indeed  to  say  that  any,  even  of  the 
worst,  could  be  entirely  dispensed  with.  But  insects 
in  excess,  which  we  most  certainly  should  have  if  the 
'  militia '  were  withdrawn,  would  change  the  world  from 
'  green '  to  brown,  and  cause  a  general  famine.  And 
the  question  before  us  is :  will  we  share  with  the  birds, 
or  have  all  devoured  by  insects  ? 

A  few  words  as  to  what  in  temperate  latitudes  may 
be  regarded,  perhaps,  as  the  farmer's  three  worst 
enemies  —  cockchafers,  daddy-long-legs,  and  click- 
beetles  or  skip-jacks.  It  is  in  the  grub-state  that  most 
insects  are  chiefly  mischievous,  for  this  is  their  grand 
eating-time;  eating  is  then  their  sole  business,  and 
they  eat  for  their  whole  lives.  For  when  they  get 


Nature  s  Militia  329 

their  wings  they  usually  want  so  little  food,  and  that 
of  such  a  kind  that  no  one  can  grudge  it  them.  A 
caterpillar  eats  leaves;  for  instance,  and  devours  them 
greedily,  whereas  a  butterfly  takes  but  a  sip  of  nectar, 
the  loss  of  which  is  no  injury  to  even  the  most  delicate 
flower.  Yet,  as  the  winged  insects  lay  multitudes  of 
eggs,  they  cannot  be  called  harmless,  and  some  few  of 
them  even  do  a  good  deal  of  eating  on  their  own 
account.  Cockchafers,  for  example,  eat  leaves,  and 
sometimes  strip  whole  woods,  while  their  grubs  devour 
roots.  Daddy-long-leg  grubs  (turnip-fly)  are  equally 
destructive,  and  so  terribly  hardy  that  they  thoroughly 
deserve  their  name  of  leather-jackets.  For  they  are 
very  little  affected  by  weather,  and  may  be  frozen  stiff, 
or  lie  under  water  for  a  couple  of  days,  and  yet  be  just 
as  lively  as  ever  afterwards.  Insects,  indeed,  often 
take  a  great  deal  of  killing,  and  will  live  through  frosts, 
especially  in  the  chrysalis- state,  when  the  poor  birds 
perish  by  hundreds. 

As  for  the  grub  of  the  click-beetle,  its  very  name  is 
enough  to  make  a  farmer  shudder,  for,  as  the  wire- 
worm,  it  is  only  too  well  known.  For  five  whole  years 
it  remains  a  grub,  eating  all  the  time.  And  it  will  eat 
almost  anything  in  the  way  of  vegetable-food,  turnips 
as  well  as  sprouting  corn,  or  hops,  and  grass-roots  as 
well  as  any  of  these.  Where  the  young  corn  is  strong, 
it  will  sometimes  recover  from  having  its  first  shoot 
eaten  off  just  below  the  ground,  and  will  even  send  up 
two  or  three  shoots  instead  of  one ;  but  when  the  plants 
are  weak,  as  they  often  are  on  light,  chalky  soil,  there 
the  wire-worm  destroys  sometimes  the  half,  and  occa- 
sionally the  whole,  of  a  crop. 

To  help  him  in  the  perpetual  war  which  has  to  be 


33O  Natures  Militia 

waged  with  these  three  special  foes,  the  farmer  has 
friends — the  sparrow  -again,  and  the  rook,  jackdaw, 
magpie,  jay,  all  the  smaller  birds  of  prey,  in  fact,  and 
many  of  the  larger;  and  besides  these,  he  has  the 
stoat,  weasel,  mole  and  hedgehog,  which  last,  though 
much  persecuted,  is  most  useful,  and  quite  inoffensive. 

The  battle  about  the  rook  is  only  less  fierce  than 
that  about  the  sparrow,  but  while  it  is  no  doubt  true 
that  he  does  uproot  some  plants  in  his  search  for  grubs, 
that  he  does  steal  a  little  corn,  and  that,  when  insects 
are  scarce,  or  rooks  too  many,  he  even  attacks  the 
crops,  still,  where  rooks  are  poisoned,  wire-worm 
increases  and  crops  fail.  One  rook  will  have  as  many 
as  three  dozen  daddy-grubs  or  click-beetles  in  its  crop 
at  once,  and  the  birds  go  over  the  ground  yard  by  yard 
in  the  most  systematic  manner,  working  from  early 
dawn  till  evening,  each  bird  catching,  it  is  said,  at  least 
fifty  wire- worms  in  the  day. 

In  some  parts  of  the  country  the  rooks  are  often 
joined  at  their  work  in  the  furrows  by  large  flocks  of 
gulls,  titmice  and  others,  which  appear  when  ploughing 
begins,  and  go  away  when  the  furrows  are  cleared, 
without  taking  any  pay  from  the  farmer,  except  in  the 
shape  of  the  insect-food  which  he  is  glad  to  be  rid  of. 

Other  very  useful  biuds,  which  must  be  passed 
over  with  a  mere  mention,  are  the  various  species  of 
plover,  the  partridge,  and  the  pheasant — a  couple  of 
which  will  eat  1,500  wire- worms  at  a  meal — the  thrush 
and  the  landrail,  both  of  which  clear  the  fields  of 
snails  and  slugs,  and  the  swallow,  martin  and  swift, 
without  whom  the  air  would  be  so  choked  with  flies  as 
to  be  simply  unbreathable. 

So  much,   then,  for  the  services,    the   incalculable 


Nature's  Militia  331 

and  indispensable  services,  of  the  '  militia.'  We  have 
seen  something  of  these,  and  we  have  seen,  too,  how 
surely  punishment  has  followed  where  the  birds  have 
been  exterminated ;  but  there  is  a  word  or  two  to  be 
said  on  the  other  side  of  the  question. 

It  is  very  rash  for  man  to  interfere  with  nature  by 
exterminating  any  one  class  of  the  labourers  employed, 
whether  in  the  tilling  or  in  the  protection  of  the  fields, 
cultivated  or  uncultivated  ;  but,  at  the  same  time,  it  is 
hardly  less  rash  for  him  to  interfere  in  the  other  direc- 
tion, and  to  encourage  these  same  labourers  overmuch ; 
or  even,  because  they  are  found  useful  in  one  part  of 
the  world,  to  conclude  hastily  that  they  must  be  equally 
useful  in  another. 

Thistles  do  not  overwhelm  us,  and  swamp  other 
vegetation,  in  Europe ;  but  he  was  a  very  rash  man 
who  imported  a  sack  of  thistle-seed  into  South 
America  and  scattered  it  broadcast  about  Valparaiso, 
with  an  idea  of  providing  useful  fodder  for  cattle! 
The  thistle  took  to  the  soil  and  climate  amazingly, 
and  having  nothing  to  check  its  increase,  as  it  has  at 
home,  quickly  spread  over  large  tracts  of  country,  to 
the  great  inconvenience  of  the  cultivators. 

Then,  someone  may  be  inclined  to  say,  why  not 
import  birds  to  eat  the  seed  ?  But  things  in  nature 
are  so  exactly  balanced  that  even  this  step  would 
probably  be  found  to  have  its  disadvantages,  and 
possibly  the  birds  might  turn  out  to  be  even  worse 
than  the  thistles.  The  sparrows  imported  into  the 
United  States,  for  instance,  and  at  first  petted  and 
made  much  of,  have  so  thriven  and  multiplied  that 
they  are  now  a  pest,  and  generally  hated.  But  the 
mischief  is  done,  and  is  not  to  be  so  easily  undone. 


33 2  Natures  Militia 

They,  like  the  thistles,  have  had  things  their  own 
way,  for,  as  there  were  no  sparrows  in  these  parts 
before,  naturally  no  special  checks  to  their  undue 
multiplication  had  been  provided. 

In  Europe  these  checks  have  been  provided  ;  but 
here,  again,  man  has  too  often  interfered  with  the  wise 
arrangements  of  nature,  and  when  he  has  disturbed 
the  balance  and  brought  upon  himself  a  plague  of 
sparrows  and  other  small  birds,  then,  instead  of 
blaming  his  own  want  of  foresight,  he  proceeds  to 
wage  a  war  of  extermination  on  these  offenders,  only 
to  find  himself  eaten  up  with  grubs  a  little  later. 

Of  course,  if  sparrows  and  other  small  birds  are 
allowed  to  increase  until  there  are  not  grubs  enough 
to  feed  them,  they  will  naturally  take  whatever  else 
they  can  find.  But  it  is  unfair  to  blame  the  sparrow 
for  what  is  the  farmer's  own  fault. 

The  natural  checks  provided  for  keeping  the  small 
birds  in  their  proper  place  are  the  birds  of  prey ;  and 
these — many  of  the  larger,  and  all  the  smaller — not 
only  kill  small  birds  for  their  own  eating,  but  feed 
their  young  entirely  upon  beetles,  grubs,  caterpillars, 
flies,  slugs,  snails,  and  the  various  insects  which  attack 
the  green  things.  Many  of  them,  too,  hunt  by  night, 
and  so  destroy  the  night-flying  moths  and  beetles 
which  escape  other  birds. 

Yet  birds  of  prey,  especially  owls  and  hawks,  are 
relentlessly  persecuted  by  farmers  and  keepers,  because 
they  occasionally  steal  a  young  chicken,  or — more 
heinous  offence  still — young  pheasants  and  partridges, 
and  perhaps,  yet  more  often,  they  are  killed  because  it 
is  the  fashion  to  kill  them. 

But  even  owls  and   hawks    have  their    avengers. 


Natures  Militia  333 

Sparrows,  multiplied  to  excess,  take  to  thieving,  and 
commit  great  depredations  in  the  fields ;  and  still 
worse  are  the  plagues  of  mice,  which  mar  the 
land. 

In  Scotland  and  the  north  of  England  there  has 
been  a  great  outcry  of  late  against  the  swarms  of  mice 
and  rats  which  waste  the  fields  and  rob  the  barns, 
doing  far  more  damage  than  the  sparrows.  But  why 
this  increase  in  sparrows  and  mice  ?  Because  the 
owls,  hawks,  stoats  and  weasels  have  been  killed  off. 
Just  that,  and  nothing  else. 

Owls  are  the  very  best  mousers  possible — better  than 
the  best  cats.  One  pair  of  owls  have  been  seen  to 
take  as  many  as  eleven  mice  to  their  nest  in  the  course 
of  a  single  evening.  Ravens,  crows,  hawks,  magpies 
and  jays  all  hunt  mice,  as  well  as  cockchafers  and  other 
insects,  as  already  said  ;  and  the  young  of  the  brown 
owl  are  fed  with  anything,  from  snails  even  to  kittens 
and  puppies.  But  the  young  of  the  barn-owl  require 
a  steady  supply  of  fresh  mice,  and  she  herself  makes 
mice  almost  her  sole  diet,  so  that  she  benefits  not  only 
corn  but  clover.  For  if  it  is  true  that  the  crop  of 
clover-seed  depends  to  a  great  extent  upon  the  number 
of  cats  in  the  neighbourhood,  surely  the  presence  or 
absence  of  those  grand  mousers,  the  owls,  must  make 
at  least  as  much  difference  to  it.  For  mice  are  very 
much  addicted  to  eating  humble-bees,  as  well  as  corn ; 
and  as  the  common  purple  clover  is  fertilized  by 
humble-bees  only,  there  can  be  no  seed  where  humble- 
bees  are  wanting,  which  they  certainly  would  be  if 
mice  were  allowed  to  multiply  unchecked. 

Whether  or  no  people  in  this  land,  other  than  the 
naturalists,  are  connecting  the  grievous  plague  of 


334  Natures  Militia 

mice  in  Dumfriesshire  and  elsewhere  with  the  dis- 
appearance of  the  birds  of  prey,  it  is  being  clearly 
recognised  in  America  that  without  the  latter  sparrows 
are  a  sad  mistake.  In  the  States,  birds  of  prey  are 
comparatively  rare  ;  not  because  they  have  been  killed 
off,  as  with  us,  but  because  nature  had  not  provided 
them — a  very  different  matter.  But  now  that  the 
English  sparrow  has  made  himself  unpleasantly 
obtrusive,  hawks  are  being  imported  as  the  only  likely 
means  of  quelling  him.  Why  hawks  instead  of  owls 
is  not  evident,  but  it  will  be  interesting  to  watch  the 
result  of  this  second  experiment ;  for  if  the  hawks  in 
their  turn  should  increase  to  excess  they  might  prove 
even  worse  than  sparrows. 

In  some  parts  of  the  world  the  balance  of  animal 
life  established  by  nature  is  very  curious,  and  any 
interference  with  it  is  attended  by  danger.  In  some 
districts  in  India,  for  instance,  the  tiger  is  as  useful 
to  the  farmer  as  owl  and  hawk  are  here.  If  he  kills 
off  the  tigers,  as  his  English  brother  kills  the  birds 
of  prey,  then  the  deer  multiply  and  eat  his  crops  ;  and 
on  the  other  hand,  '  if  he  kills  off  the  deer,  the  tigers 
kill  him,  for  even  a  tiger  must  live  !'  so  that  on  the 
whole  he  finds  it  better  not  to  interfere. 

We  have  already  mentioned  the  stoat  and  weasel  as 
most  useful  in  keeping  down  the  numbers  of  rats, 
mice  and  rabbits,  and  the  hedgehog  as  being  a 
devourer  of  insects,  with  absolutely  no  bad  habits 
to  take  from  its  value.  Yet  all  these  are  persecuted 
without  mercy  as  '  vermin,'  chiefly  from  habit,  in  all 
probability;  for  the  old  stories  as  to  the  hedgehog's 
milking  the  cows,  and  rolling  itself  on  fruit  and  eggs, 


Nature's  Militia  335 

which  it  carries  off  on  its  prickles  (!),  can  hardly,  one 
would  think,  be  seriously  believed. 

Another  much-persecuted  creature  is  the  mole  ;  and 
yet  the  mole  is  always  eating  wire-worm  and  the  like, 
doing  its  very  best  for  ungrateful  man  ;  for  its  appetite 
is  voracious,  and  it  is  quite  unable  to  survive  even  a 
short  fast.  The  mole  is  not  without  his  admirers, 
however,  in  spite  of  his  certainly  trying  way  of  throw- 
ing up  hillocks,  and  one  of  his  friends  says  :  '  As  surely 
as  the  farmer  destroys  the  mole,  so  will  he  have  in  ex- 
change wire-worm  and  turnip-fly.' 

Insects  are,  as  a  whole,  such  enemies  of  vegetation 
that  we  are  apt  to  condemn  them  in  a  body.  Yet 
besides  the  many  which  convey  pollen  there  are  a  few 
others  which  deserve  honourable  mention,  and  even 
the  name  of  friends.  These  few  are  positive  bene- 
factors, for  they  leave  the  green  things  alone  themselves 
and  prey  upon  other  mischievous  insects. 

Among  these  insect-friends  is  the  lady-bird,  to  whom, 
as  an  American  writer  says,  '  we  should  take  off  our 
hats,'  for  it  destroys  those  terrible  pests,  thrips  and 
green-fly. 

Wasps  carry  off  flies  and  caterpillars  to  feed  their 
young  grubs;  and  some  species  of  jchneumon-fly 
deposit  their  eggs  in  the  chrysalids  of  moths  and 
butterflies,  as  well  as  in  grubs  and  caterpillars,  thereby 
killing  them.  But  of  all  insects,  perhaps  some  of  the 
beetles  are  the  most  useful,  for,  both  in  the  grub  and 
in  the  winged  state,  they  catch  and  devour  living  prey. 

To  sum  up :  without  insects  many  plants  would  be 
unable  to  produce  seed,  and  so  must  in  time  die  out ; 
without  the  small  birds,  insects  woqld  increase  so 


Nature's  Militia 

much  that  all  green  things  would  be  destroyed ;  and 
without  the  birds  of  prey  to  keep  the  number  of  small 
birds  within  bounds,  not  only  would  farming  be  quite 
impossible,  but  wild  plants  would  also  suffer ;  for,  wher 
the  insects  were  devoured,  or  even  very  greatly  reduced 
in  numbers,  the  plants  dependent  upon  them  for  help 
would  be  seedless,  and  the  remainder  would  be  so 
plundered  of  their  seed  by  flocks  of  hungry  birds,  that 
little  would  be  left  for  sowing. 

Both  insects  and  birds,  then,  are  the  enemies  of 
vegetation  when  their  numbers  are  multiplied  to 
excess;  but  without  them,  there  would  be  no  vege- 
tation at  all. 


XXII. 

MAN'S  WORK  ON  THE  FARM. 

HITHERTO  we  have  been  considering  how  the  world's 
fields  are  cultivated  when  the  work  is  left  entirely  to 
those  who  labour  without  hands — to  air,  wind,  frost, 
rain,  snow,  sun,  glacier,  river,  earthquake,  volcano ;  to 
the  worms  and  others  which  plough  the  soil ;  to  the 
insects  which  act  the  part  of  pollen-carriers  between 
the  flowers,  and  to  the  birds  which  keep  the  insects  in 
order,  and  help  the  winds  and  waves  to  scatter  the 
seed.  These  and  many  other  workers  not  here  enu- 
merated, are  at  work  constantly  in  the  fields  which 
man  has  taken  under  his  own  care,  as  well  as  in  those 
still  left  entirely  to  nature.  Together  they  keep  the 
world  green,  and  they  would  keep  it  green  if  there 
were  not  a  man  in  it ;  for  they  are  quite  able  to  do 
without  his  help  in  the  matter,  though  he  would  be 
entirely  helpless  without  theirs. 

But  man  has  done  much  to  modify  the  result  of  their 
combined  labours,  not  only  in  that  small  proportion  of 
the  earth  which  he  cultivates  or  occupies,  but  even 
beyond.  Where  men  dwell  together  in  numbers,  there 
the  earth  is  necessarily  less  green,  for  towns,  cities, 
roads,  railways,  have  invaded  the  woods  and  fields,  and 


Man's  Work  on  the  Farm 

have  not  only  turned  out  their  inhabitants,  animal  and 
vegetable,  but  have  made  their  influence  felt  over  a 
much  wider  space  than  that  which  they  actually  cover. 
Even  where  wild  plants  have  been  turned  out  only  to 
make  way  for  cultivated  ones,  the  result  has  been 
similar  in  some  degree.  The  earth  bears  better  crcps, 
no  doubt,  at  least  from  man's  point  of  view,  but  they 
are  less  crowded,  and  the  fields  are  bare  for  some  part 
of  the  year. 

But  besides  cutting  down  woods  and  forests  and 
clearing  away  bush,  man  has  drained  fields,  as  well  as 
marshes,  he  has  cut  canals,  and  he  has  taken  plants 
from  one  land  to  another  and  from  one  hemisphere  to 
another,  in  many  cases  intentionally,  but  in  many 
others  quite  unintentionally. 

Other  changes,  though  man  has  been  the  cause  of 
them,  have  taken  place  altogether  without  design  on 
his  part ;  and  even  where  he  has  intended  to  make 
some  change,  he  has  not  seldom  found  that  he  has 
done  a  good  deal  more  than  he  meant,  and  has  in  fact 
started  a  whole  series  of  changes. 

Trees,  for  instance,  are  cut  down  for  the  sake  of  the 
timber  they  will  furnish,  and  nothing  else,  perhaps. 
But  a  great  deal  more  is  done  than  merely  to  take 
away  so  many  loads  of  wood.  To  begin  with,  the  soil 
is  exposed  and  dried,  and  the  plants  which  have 
flourished  in  the  shade  and  moisture  will  die  off.  The 
insects  which  fed  upon  the  plants  will  die  off  too,  and 
the  birds  which  fed  on  the  insects  and  found  shelter  in 
the  trees  will  be  driven  away. 

If  the  trees  are  simply  cut  down,  and  the  ground  is 
left  unoccupied,  it  will  be  gradually  taken  possession 
of  by  other  plants  or  trees.  In  Germany,  where  the 


Man's  Work  on  the  Farm  339 

ground  has  been  cleared  of  wood  and  then  left  to  itself, 
it  is  covered  in  a  few  years,  first  with  shrubs,  then 
with  trees,  chiefly  of  the  pine  tribe.  In  eight  years,  it 
will  become  a  coppice  with  saplings  five  or  six  feet 
high ;  and  all  this  without  any  further  interference  on 
the  part  of  man. 

Man  makes  the  vacancy,  and  nature,  if  only  let 
&lone,  fills  it  again.  There  are  parts  of  the  United 
States  where  pine-woods  have  been  cut  down  for 
railway  purposes,  and  have  been  at  once  followed  by 
oaks,  planted  by  some  or  other  of  nature's  many 
labourers.  Why  pines  should  not  have  sprung  up 
again,  when  their  seeds  must,  one  would  imagine, 
have  been  present  in  the  soil,  seems  to  be  one  of 
the  many  questions  still  waiting  to  be  answered; 
but  it  is  a  well-known  fact  that  in  many  places 
where  forests  are  cut  down,  trees  of  an  entirely 
different  kind  do  spring  up  in  their  place.  And  of 
course  different  trees  mean  different  insects,  and 
different  birds. 

Mr.  Darwin  mentions  some  remarkable  changes  of 
this  sort  brought  about  simply  by  the  enclosure  and 
planting  with  Scotch  fir  of  a  very  barren  heath  in 
Staffordshire  never  before  touched  by  man.  In  five- 
and-twenty  years,  the  vegetation  of  the  planted  and 
unplanted  portions  had  become  so  different  that  the 
soil  might  have  been  supposed  to  be  of  quite  distinct 
kinds.  Within  the  plantation  there  were  fewer  heath- 
plants,  but  there  were  also  twelve  species  of  other 
plants,  not  counting  grasses  and  sedges,  which  were 
not  to  be  found  on  the  heath  at  all.  Six  species  of 
insect-eating  birds,  too,  were  common  in  the  planta- 
tion, but  did  not  stray  outside  it ;  while  two  or  three 


340  Man's   Work  on  the  Farm 

others,  quite  distinct  from  these,  were  to  be  found  only 
on  the  heath.  For  change  in  the  vegetation  had  been 
followed  by  a  corresponding  change  both  in  the  insect* 
life  and  in  the  bird-life. 

Not  a  marsh  nor  a  field  can  be  drained,  not  a  canal 
can  be  cut,  not  a  railway  or  even  a  road  can  be  made, 
nor  a  house  built,  without  making  some  change,  and  in 
some  cases  a  very  great  change,  in  the  vegetation  of 
the  place  or  immediate  neighbourhood.  As  for  the 
growth  of  towns  and  cities,  that  affects  far  more  than 
the  immediate  neighbourhood ;  for  not  only  is  many  a 
field  covered  with  bricks  and  mortar,  but  the  smoke 
from  the  chimneys  and  the  increased  traffic  on  the 
roads  have  their  effect  upon  vegetation,  sometimes  for 
miles  round. 

When  to  houses  are  added  factories,  the  evil  influ- 
ence is  felt  still  more  widely,  and  that  even  by  lichens. 
Lichens  are  such  very  passive-looking  vegetables,  so 
little  life-like,  and  so  largely  composed  of  mineral 
matter,  that  one  is  apt  to  fancy  they  cannot  be 
sensitive.  And  they  are  in  many  respects  very  hardy, 
as  we  have  seen.  But  they,  too,  have  their  limits 
of  endurance.  They  may  stand  both  biting  cold  and 
parching  heat ;  but  smoke  kills  them,  especially  the 
larger  leafy-looking  species,  such  as  grow  on  the 
trunks  of  trees.  They  flourished  formerly  in  the 
woods,  seven  miles  from  Newcastle,  and  might  flourish 
there  still,  but  for  the  change  in  the  atmosphere,  for 
nothing  else  is  altered.  But  the  factories  and  collieries, 
though  several  miles  off,  have  polluted  the  air;  the 
trunks  and  branches  of  the  trees  have  acquired  the 
grimy  look  which  they  wear  in  cities,  and  all  the  larger 
lichens,  and  most  of  the  smaller,  have  been  killed  by 


Maris  Work  on  the  Farm  34! 

the  soot.  Lichens  have  also  disappeared  from  Kew 
Gardens,  and  are  rare  in  Epping  Forest. 

Changes  of  this  sort  are,  however,  very  small  com- 
pared with  those  which  have  followed  the  destruction 
of  primeval  forests,  the  introduction  of  agriculture, 
the  wanderings,  and  even  wars,  of  the  human  race, 
the  voyages  of  traders,  and  the  discovery  of  new  lands. 

Those  who  are  accustomed  to  cultivate  the  soil,  in 
however  rude  and  primitive  a  fashion,  naturally  carry 
with  them  on  their  wanderings  the  seeds  of  such 
plants  as  they  have  found  useful.  This  is  true  even 
of  such  nomads  as  the  gipsies,  whose  attempts  at 
agriculture  have  been  necessarily  of  a  very  limited 
description,  since  their  crops  had  to  be  sown  and 
reaped  during  the  short  time  that  they  remained 
stationary. 

But  besides  carrying  some  seeds  purposely,  travellers 
of  all  sorts,  whether  nomads  or  not,  frequently  carry 
others  by  pure  accident,  and  quite  unconsciously. 
They  mean  to  take  with  them  only  cultivated  plants, 
but  somehow  or  other,  in  this  way  and  in  that,  the 
weeds  contrive  to  get  taken  too.  It  is  often  quite 
impossible  to  say  how  they  have  been  brought,  but 
there  they  are.  This  is  especially  the  case  with  what 
may  be  called  cultivated  weeds — those  which  are  found 
in  cultivated  fields  and  nowhere  else ;  for,  unless  great 
care  is  taken,  their  seeds  are  very  apt  to  be  mixed 
with  those  of  the  crop,  and  then  both  are  sown  to- 
gether. Clover  and  grass  seeds  are  especially  liable 
to  adulteration  of  this  sort ;  broom-rape  and  dodder 
are  conveyed  in  the  one,  and  worthless  grasses,  and 
many  another  weed,  sneak  in  with  the  others. 

Many  seeds  are  conveyed,  also,  in  forage;  and  in 


342  Matis   Work  on  the  Farm 

1870,  during  the  Franco-Prussian  war,  seeds  were  thus 
brought  to  France  by  troops  from  Algiers,  and  were 
scattered  in  different  places,  where  they  germinated 
and  grew  up,  but  apparently  found  soil  or  climate  un- 
congenial, and  died  out  in  the  course  of  two  or  three 
years.  Had  they  travelled  south  instead  of  north,  they 
might  have  become  permanent  colonists. 

Again,  the  ballast  of  vessels  is  a  very  favourite 
hiding-place  for  seeds ;  and  foreign  plants  often  first 
spring  up  in  the  neighbourhood  of  sea-ports,  being 
brought  not  only  in  this  way  but  in  others  less  obvious. 
Intercourse  of  any  kind  with  foreign  lands  is  almost 
sure  to  lead  to  the  introduction  of  foreign  plants,  not 
only  without  any  effort  on  man's  part,  but  often  quite 
against  his  wishes. 

Fleeces  from  South  America,  Mexico,  and  the  Cape, 
have  been  the  means  of  bringing  seeds  to  some  of  the 
valleys  of  Gloucestershire,  and  to  the  Pont  Juvenal, 
near  Montpellier,  where  they  were  washed  and  spread 
out  to  dry ;  and  in  many  cases  these  seeds  have  not 
only  germinated  but  blossomed,  though  they  have  not 
lasted  more  than  a  season  or  two. 

No  one,  probably,  would  wish  to  assist  that  trouble- 
some weed,  the  wayside  plantain,  to  migrate,  yet,  if 
the  tradition  of  the  American  Indians  is  to  be  trusted, 
it  has  followed  the  white  man  all  over  the  western 
continent.  The  seeds  are  very  minute,  though  they 
are  not  otherwise  specially  capable  of  dispersing  them- 
selves ;  and  if  once  they  managed  to  slip  in  anywhere, 
they  would  be  carried  unnoticed.  Certain  it  is  that 
the  Indians  look  upon  this  plantain  as  having  come 
with  the  white  man ;  for  they  call  it  the  '  White  Man's 
Foot.'  Botanists  have  been  rather  sceptical  on  the 


Marls  Work  on  the  Farm  343 

Subject,  as  there  is  a  plantain  acknowledged  by  all  to 
be  a  native  of  America,  which  is  so  like  the  stranger 
as  to  have  been  confounded  with  it  for  some  time, 
except  by  the  Indians  and  the  cows.  The  latter  will 
eat  the  native  plant,  but  not  the  other ;  and  as  the  two 
are  now  distinguished  by  botanists,  it  seems  likely  that 
the  Indians  are  after  all  right  in  their  tradition. 

One  weed,  the  Canadian  fleabarie,  made  its  way  to 
Europe  by  very  singular  means.  A  single  seed  came 
over  accidentally  in  a  stuffed  bird.  This  was  purposely 
sown,  no  doubt  out  of  curiosity,  and  then  the  deed  was 
done,  and  the  result  was  beyond  control.  For  the 
fleabane  has  downy  seeds,  and  these  flew  away  and 
spread  themselves  all  over  Europe  without  any  further 
assistance. 

Few  weeds  have  come,  or  are  ever  likely  to  come, 
from  China,  by  all  accounts,  for  the  population  is  so 
dense,  and  labour  so  abundant  and  so  careful,  that 
none  of  the  cultivated  districts  are  good  hunting- 
grounds  for  the  botanist.  When  one  thinks  of  the 
many  plants  to  be  found  in  our  fields  and  meadows, 
besides  those  sown  and  cultivated  by  the  farmer,  it  is 
strange  to  learn  that,  with  the  exception  of  some  few 
water-plants  in  the  rice -fields,  the  botanist  finds 
scarcely  any  plants  in  the  fields  of  China  but  such  as 
are  cultivated.  That  is  to  say,  he  may  find  stray  plants 
of  millet  among  the  beans,  or  lentils  among  the  corn, 
and  so  on ;  but  of  '  weeds '  pure  and  simple,  unculti- 
vated plants,  he  finds  scarcely  a  specimen,  and  anything 
answering  to  the  gay  poppies  and  rampant  bindweed 
of  our  corn-fields  is  absolutely  unknown  ! 

It  is  a  curious  fact  that  almost  all  the  really  trouble- 
some weeds  in  the  world  are  emigrants  from  Europe. 


344  Mans  Work  on  the  Farm 

But  before  we  consider,  in  their  proper  order,  a  few 
of  the  more  important  changes  which  have  taken  place 
in  the  vegetation  of  different  lands,  a  word  or  two  must 
be  said  about  names. 

It  is  necessary  to  be  cautious  about  accepting 
popular  names,  for  these  are  often  given  without  much 
reason. 

The  Indian  fig,  or  prickly  pear,  is  neither  fig  nor 
pear,  but  an  American  cactus.  The  Jerusalem  arti- 
choke is  an  American  sunflower,  in  Italian  Girasole 
(Turnesol),  which  was  corrupted  into  'Jerusalem,'  and 
it  was  called  an  '  artichoke '  because  the  tubers  some- 
what resembled  in  taste  the  heads  of  the  real  artichoke. 

As  for  the  names  'apple'  and  'pear,'  they  have  been 
used  in  the  most  reckless  manner  both  in  ancient  and 
modern  times.  The  Persian  '  apple '  of  the  Greeks  and 
Romans  was  the  Chinese  peach,  and  their  Punic 
'apple*  was  the  Persian  pomegranate.  The  'golden 
apple '  of  the  Italian  is  not,  as  one  might  suppose,  a 
pippin,  but  the  tomato.  The  'alligator  pear'  of 
Mexico  is  not  a  pear,  nor  has  it  any  connection  with 
alligators.  Its  native  name  is  ahuaca,  corrupted  by  the 
French  into  avocat  and  avocaiier,  suggestive  of  some 
equally  mysterious  connection  with  lawyers,  with 
whom,  however,  it  has  as  little  to  do  as  the  pomme 
ft  acajou  has  with  mahogany.  As  to  the  red  and  white 
'  currants'  of  our  gardens,  what  right  had  they  to  steal 
the  names  of  the  small  grapes  of  Corinth,  which  we 
now  call  grocer's  currants  for  distinction  ? 

The  potato  is  too  curious  an  instance  of  this  kind 
of  thing  to  be  passed  over.  By  French  and  Germans 
it  has  been  called  the  '  earth-apple,'  and  by  the 
Hungarians  the  'earth-pear';  but  the  English 


Mans   Work  on  the  fann  345 

Cannot  be  said  to  be  much  more  felicitous  than  these. 
For  the  potato,  like  its  cousins  the  tomato  and  the 
tobacco,  is  a  nightshade ;  and  the  batata,  after  which 
it  is  named,  is  a  convolvulus,  a  native  of  Brazil.  The 
Brazilian  batata  bears  tubers,  which  were  imported 
into  England  from  Spain  in  considerable  quantities 
before  the  'potato'  was  known,  or  at  least  before  it 
came  into  general  use ;  but  the  two  are  much  alike  in 
appearance,  and  the  later  comer  was  so  much  the 
more  popular,  that  the  name  of  the  convolvulus  was 
transferred  to  it,  and  the  true  batatas  came  to  be  known 
as  'sweet  potatoes/  To  make  the  confusion  still 
worse,  the  potato  has  been  introduced  into  Brazil, 
where  it  was  formerly  unknown,  and  is  there  called 
the  '  English  batata.9 

As  we  have  no  means  of  telling  when  the  first 
migrations  of  man  took  place,  it  is  quite  vain  for  us  to 
guess  at  the  date  of  the  earliest  migrations  of  such 
plants  as  he  carried  with  him.  The  earliest  wander- 
ings of  both  are  equally  involved  in  obscurity,  but  we 
know  that  they  began  long  before  history  has  anything 
to  say  about  them ;  and  we  know,  too,  that  cultivated 
plants  had  been  brought  from  Asia  to  Europe  even  in 
these  far-off,  dateless  ages. 

The  lake-dwellers  of  Switzerland,  who  built  their 
habitations  on  piles,  and  used  none  but  stone  imple- 
ments, knew  something  of  agriculture ;  and,  from  the 
blackened  remains  of  grain  found,  we  know  that  they 
cultivated  three  kinds  of  wheat,  two  of  barley,  and  two 
of  millet,  which  are  none  of  them  natives  of  Europe, 
and  must  have  been  brought  at  some  time  or  other 
from  Asia. 


346  Maris   Work  On  the  Farm 

But  if  we  cannot  say  when  the  first  corn  was  brought 
to  Europe,  still  less  can  we  say  when,  and  by  whom, 
the  various  kinds  were  first  cultivated.  It  was,  how- 
ever, at  such  a  very  remote  period,  that  they  are  none 
of  them  found  in  the  wild  state. 

The  earliest  changes  in  the  vegetation  of  Europe,  of 
which  we  have  any  historical  notice,  are  those  made  in 
the  south  of  Italy  by  the  Greek  colonists  (from  B.C.  734), 
who  brought  with  them  the  garden-rose  and  the  lily. 
On  their  arrival,  they  found  the  country  much  over- 
grown with  wood,  among  which  beech-trees  were 
especially  prominent,  but  there  were  none  of  the  plants 
and  shrubs  then  growing  there  which  we  are  accus- 
tomed to  think  of  as  particularly  belonging  to  Italy. 

We  can  hardly  imagine  Italy  without  the  myrtle, 
laurel  and  olive,  to  say  nothing  of  the  orange  and 
palm.  But  oranges  were  quite  unknown  both  to 
Greeks  and  Romans,  and  Italy  was  without  myrtles 
and  laurels  until  they  were  introduced  by  the  colonists 
and  planted  round  the  temples  of  Aphrodite  and 
Phoebus,  to  whom  these  shrubs  were  sacred.  The 
olive  was  in  like  manner  sacred  to  Pallas,  and  was 
therefore  pretty  sure  to  accompany  the  wanderers,  for 
it  is  one  of  the  trees  which  has  been  cultivated  from  time 
immemorial,  especially  in  Syria,  from  which  the  culti- 
vated olive  seems  to  have  come  originally.  Once 
introduced,  it  would  soon  spread,  for  birds  are  very 
fond  of  the  berries,  and  scatter  the  seeds  far  and  wide. 
A  wild  variety,  from  the  Punjab  and  Beloochistan,  has 
been  conveyed  by  their  means  to  Portugal,  Madeira, 
Morocco  and  the  Canary  Islands. 

But  near  Messa,  in  Morocco,  there  is  a  grove  of 
olives  planted  in  such  a  regular,  but  whimsical  fashion, 


Man's   Work  on  the  Farm  347 

that  one  cannot  suppose  it  to  have  sprung  from  the 
seeds  scattered  by  birds ;  and  if  tradition  is  to  be 
believed,  the  trees  grew  from  the  pegs  used  in  picket- 
ing the  horses  of  an  army  proceeding  to  the  Soudan. 
Owing  perhaps  to  some  sudden  alarm,  the  camp  was 
hastily  broken  up,  and  the  pegs,  cut  from  olive-trees  in 
the  neighbourhood,  were  left  behind  and  took  root. 

No  trees  but  evergreens — the  olive,  cypress,  and 
oleander — are  depicted  upon  the  walls  of  Pompeii; 
from  which  it  seems  that  the  beeches,  and  other  trees, 
had  been  either  exterminated  or  driven  into  the  moun- 
tains, or  at  least  had  ceased  to  be  in  any  way  conspicu- 
ous, by  the  time  these  works  of  art  were  executed. 

What  plants  may  have  been  introduced  purposely, 
or  accidentally,  by  the  Phoenicians,  who  had  trading 
stations  all  about  the  Mediterranean,  in  Europe  as 
well  as  in  Africa,  we  have  no  record  to  tell  us;  but, 
judging  by  what  we  have  seen  in  other  instances,  it  is 
impossible  to  suppose  but  that  some  plants  followed, 
or  were  conveyed  by  them  to  the  various  coasts  they 
visited.  And  their  voyages  extended  westwards  as  far 
as  Britain,  and  south  as  far  as  Senegal. 

Nor  do  we  know  much  more  of  the  effects  produced 
by  the  wars  of  Greece  and  Persia,  or  the  expeditions 
of  Alexander  the  Great,  which  took  him  as  far  as 
India.  Rice  was  certainly  made  known  to  the  Greeks 
by  the  conquests  of  the  latter  ;  but  no  attempt  seems 
to  have  been  made  at  cultivating  it. 

It  is  in  the  second  century  (B.C.)  that  the  Chinese 
first  came  into  contact  with  Western  Asia,  on  the 
occasion  of  their  helping  the  Scythians  to  ravage 
the  shores  of  the  Caspian  Sea.  A  little  later,  their 
ambassador,  Chang- Kien,  followed  on  a  peaceful  mis- 


348  Man's  Work  on  the  Farm 

sion ;  and  coming  as  he  did  from  a  nation  of  agricul- 
turists, he  seized  the  opportunity  to  carry  back  with 
him  to  China  various  useful  plants,  such  as  the  bean, 
pea,  cucumber,  water-melon,  lucerne,  saffron,  sesame, 
spinach,  nut,  and  others,  hitherto  unknown  in  the  East. 
This  is  the  earliest  instance  recorded  of  the  migration 
of  cultivated  plants  eastwards.  Westwards  we  know 
they  had  travelled  long  before. 

Whether  the  ambassador  was  so  thoughtful  as  to 
bring  any  plants  with  him,  or  whether  any  came  acci- 
dentally in  his  train,  we  do  not  know ;  but  the  peach- 
tree  is  said  to  be  a  native  of  China,  where  it  has  been 
cultivated  for  ages ;  and  it  was  so  well  established  in 
Persia,  when  the  country  was  invaded  by  the  Romans, 
that  they  introduced  it  to  Europe  as  the  *  Persian 
apple.'  The  Romans,  too,  about  B.C.  68,  brought 
from  Pontus  or  Armenia  the  first  cultivated  cherry- 
tree  ;  and  it  is  said  that  a  tree  laden  with  fruit  figured 
in  the  triumph  of  the  victorious  consul.  Cherries 
became  at  once  so  popular  that,  as  Pliny  says,  '  in  less 
than  a  hundred  and  twenty  years  after,  other  lands 
had  cherries,  even  as  far  as  Britain  beyond  the  ocean/ 

As  to  any  other  plants  which  the  Romans  may  have 
brought  to  Britain,  we  have  no  certain  knowledge ;  no 
doubt  they  cultivated  here  all  such  plants  as  they 
found  useful  at  home,  so  far  as  the  climate  would  allow 
them ;  but  they  have  at  least  the  credit  of  having 
brought  and  left  with  us  two  wild  plants,  the  columbine 
and  the  Roman  nettle.  The  nettle  is  one  of  several 
plants  which  are,  it  is  said,  sure  to  follow  the  steps  of 
the  European  wherever  he  goes ;  the  plantain,  goose- 
foot,  and  fennel  are  others. 

But,  according  to  the  old  botanists,  the  seed  of  the 


Man's  Work  on  the  Farm  349 

large  Roman  nettle  was  purposely  brought  by  the 
Roman  soldiers,  'who  sowed  it  for  their  use,  to  rub  and 
chafe  their  limbs,  being  told  before  they  came  from 
home  that  the  climate  of  Britain  was  so  cold  that  it 
was  not  to  be  endured  without  some  friction  to  warm 
their  blood/ 

However  this  may  be,  the  Roman  nettle,  which  is 
a  larger  species,  and  endowed  with  more  venomous 
'  stings '  than  the  common  stinging-nettle,  is  rare  in 
England.  But  it  formerly  abounded  in  the  streets  of 
Romney,  and,  though  driven  out  of  the  town,  still 
flourishes  in  the  neighbourhood.  Now,  it  was  near 
Romney  that  Julius  Caesar  landed,  though  the  town 
does  not  take  its  name  from  the  Romans,  but  from  a 
Saxon  word  signifying  '  marsh.' 

It  was  not  until  Roman  times  that  the  date-palm 
was  brought  to  Italy;  and  then,  as  it  did  not  bear 
fruit,  it  could  neither  run  wild  nor  make  itself 
thoroughly  at  home,  and  was  therefore  dependent 
upon  the  care  of  man.  But  the  northern  barbarians, 
who  overran  the  empire  in  later  times,  cared  nothing 
for  a  tree  which  was  only  beautiful,  and  therefore 
allowed  it  to  die  out,  and  Italy  was  without  palms 
again,  until  the  Saracens  brought  them  back. 

The  coming  of  the  Arabs,  or  Saracens,  made  a  vast 
change  in  the  vegetation  of  the  lands  of  the  Mediter- 
ranean ;  for,  destructive  as  they  were  in  some  respects, 
they  had  the  Eastern  respect  for,  and  love  of,  trees ; 
and  though  their  power  did  not  extend  nearly  as  far  to 
the  east  as  did  that  of  the  Romans,  it  was  they,  and 
not  the  Romans,  who  brought  to  the  Mediterranean 
the  many  Asiatic  plants  which  we  are  now  inclined  to 
think  must  always  have  been  there. 


350  Man's   Work  on  the  Farm 

The  Romans,  though  they  had  colonies  all  round 
the  shores  of  the  inland  sea,  made  na  such  changes 
in  its  vegetation  as  those  which  followed  the  coming 
of  the  Saracens.  It  is,  indeed,  curious  to  reflect 
how  much  Europe  owes  in  the  way  of  beautiful 
trees  and  flowers,  and  of  useful  plants,  not  only  to 
the  fanatical,  blood-thirsty  Arab,  but  also  to  the  'un- 
speakable '  Turk,  who  brought  us  the  horse-chestnut, 
tulip,  and  other  ornamental  plants.  The  Arab  of 
to-day  carries  with  him  the  seeds  of  his  favourite 
plants,  fruits  and  vegetables,  even  when  he  is  on  his 
slave-making  expeditions  in  the  heart  of  Africa.  And 
wherever  he  settles,  if  it  be  but  for  a  year  or  two, 
there  he  makes  a  garden. 

It  was  so,  also,  in  the  eighth  and  following  centuries. 
Egypt,  North  Africa,  Spain,  the  Balearic  Islands, 
South  France,  Sardinia,  South  Italy,  Sicily,  the  Levant 
— all  felt  his  influence,  for  wherever  he  went  he  tried 
to  make  the  new  country  as  home-like  as  possible. 

The  planting  of  the  first  date-palm  in  Spain  was 
an  important  ceremony,  performed  by  the  first  caliph, 
Abdurrahman  himself,  in  a  garden  near  Cordova,  his 
capital ;  and  this  tree  is  said  to  have  been  the  ancestor 
of  all  the  palms  of  modern  Spain,  including  the  forest 
of  60,000  fruit-bearing  trees  in  Valencia. 

In  Calabria  and  Sicily  the  palm  was  allowed  almost 
to  die  out  again  when  the  Saracens  were  gone,  and  for 
the  same  reason  as  before — because  it  did  not  bear 
fruit ;  and  it  was  not  until  the  ceremony  of  the  blessing 
of  palms  on  Palm  Sunday  was  introduced,  that  people 
began  to  think  it  worth  cultivating  for  the  sake  of  its 
foliage  only. 

Then,  however,  the  palm  began  to  be  made  much 


Mans  Work  on  the  Farm  351 

of  in  Italy,  as  there  was  a  brisk  demand  for  its  '  leaves ' ; 
and  the  great  grove,  which  is  miles  long,  was  planted 
at  Bordighera,  simply  for  the  supply  of  these. 

Among  the  other  plants  which  the  Saracens  brought 
to  Europe,  were  the  orange  and  lemon,  the  sugar-cane, 
rice,  cotton,  saffron,  and  the  locust-tree.  The  citron- 
family,  which  includes  the  lime,  orange,  and  lemon, 
seems  to  be  a  native  of  China,  where  the  fruits  grow 
wild,  and  many  varieties  have  been  in  cultivation  for 
ages  past ;  but  how  and  when  they  travelled  west- 
wards, as  they  must  have  done  before  the  Arabs  could 
make  their  acquaintance,  we  have  no  means  of  dis- 
covering. 

Wherever  the  Arab  went,  there  fields  of  saffron 
were  sure  to  spring  up ;  for  this  was  a  flower  he 
loved  and  valued  very  highly  for  its  perfume, 
flavour,  dye,  and  medicinal  properties.  Greeks  and 
Romans  had  known  it  as  the  crocus,  and  prized  it 
too,  but  the  extreme  fondness  of  the  Arabs  for  it 
caused  it  to  be  cultivated  far  more  extensively  than 
it  had  ever  been  before ;  and  their  name  for  it, 
*  saffron,'  quite  took  the  place  of  the  classical  one. 

Rice  had  long  been  known  as  an  expensive  foreign 
article ;  but  there  had  been  no  attempt  at  cultivating 
it  out  of  Asia,  until  the  Arabs  tried  it  with  much 
success  in  the  Delta  of  the  Nile,  and  soon  after  carried 
it  further  west.  It  flourished  in  the  marshes  of 
Valencia,  and  elsewhere  in  Spain  ;  but  the  Italians 
were  only  too  successful  with  it ;  for  finding  that  it 
could  be  grown  without  difficulty,  they  turned  their 
fields  and  meadows  into  swamps,  in  such  a  reckless 
manner  that  much  illness  followed,  and  the  law 
stepped  in  and  set  strict  limits  to  its  cultivation. 


352  Man's   Work  on  the  Farm 

Large  crops  are,  however,  still  grown  in  the  plains 
of  Lombardy. 

So  much  was  done  by  the  Arabs  to  make  the  vege- 
tation of  the  East  known  in  Europe,  that  the  Crusaders 
found  little  to  bring  home  in  the  way  of  useful  plants ; 
and  the  next  important  addition  to  the  food-plants  of 
Europe,  though  that  too  came  from  Asia,  was  a  much 
more  northerly  one. 

Buckwheat  grows  wild  about  the  river  Amoor,  and 
in  some  other  parts  of  Asia,  and  as  it  made  its  first 
appearance  in  Europe  at  the  same  time  as  the  gipsies, 
early  in  the  fifteenth  century,  they  have  generally  had 
the  credit  of  introducing  it,  as  its  many  names,  such  as 
'  heathen '  and  '  Saracen '  corn,  sufficiently  testify,  for 
these  were  applied  indiscriminately  to  the  gipsies  also. 
It  seems  not  improbable  that  they  should  have  carried 
it  with  them,  for  it  grows  on  poor  soil,  and  takes  but  a 
short  time  to  come  to  perfection,  and  would  therefore 
be  well  suited  to  the  needs  of  those  who  lead  a  wander- 
ing life. 

Another  plant  which  is  said  also  to  have  followed 
the  gipsies  from  Asia  all  across  Europe  is  the  deadly 
thorn-apple,  which  is  unpleasantly  suggestive  of  some 
of  their  evil  practices. 

Hitherto  the  various  migrations  of  plants,  of  which 
we  have  any  certain  knowledge,  had  been,  with  few 
exceptions,  from  east  to  west.  And  now,  with  the 
wonderful  discovery  of  the  New  World,  fresh  fields 
were  opened  out  to  them,  still  in  the  same  direction. 
Europe  was,  as  it  were,  but  a  stepping-stone  for  many, 
on  their  way  to  the  Far  West ;  and  in  the  case  of  not  a 
few,  it  was  only  when  they  reached  the  western  hemi- 
sphere that  they  showed  what  they  were  capable  of. 


Man's  Work  on  the  Farm  353 

and  became  important  crops.  Rice,  cotton  and  sugar, 
for  instance,  were  all  grown  in  the  south  of  Europe  to 
some  extent,  after  the  Saracens  had  introduced  them 
there,  but  what  were  the  little  plantations  of  Spain 
and  Italy  compared  with  those  of  the  West  Indies  and 
America  ? 

However,  though  the  stream  continued  to  flow 
westward,  and  that  with  such  vigour  that  nearly  the 
whole  of  the  vegetable  world  of  Europe  seemed  to  be 
on  the  move,  no  sooner  was  the  New  World  discovered 
than  a  counter  movement  set  in.  The  eastern  world 
certainly  gave  more  than  it  received;  but  it  also 
received  much,  and  American  plants  are  now  so  well 
known  throughout  Europe  and  great  part  of  Asia,  that 
they  are  hardly  any  longer  looked  upon  as  foreigners ; 
and  it  is  quite  difficult  to  realize  what  the  lands  of  the 
Mediterranean,  and  even  our  own  kitchen-gardens, 
looked  like  before  the  discovery  of  America,  when  the 
blue-green,  sword-leaved  agave,  commonly  called  the 
American  aloe,  the  magnolia  and  prickly  pear,  were 
unknown  in  the  south  of  Europe ;  when  Italy  had  no 
maize,  macaroni,  or  tomatoes,  the  Irish  no  potatoes, 
and  the  Turk  no  tobacco. 

When  we  think  of  the  way  in  which  the  prickly  pear 
has  spread  over  all  the  coasts  of  the  Mediterranean, 
north  and  south,  and  of  the  broad  fields  now  devoted 
to  the  cultivation  of  maize  and  potatoes,  to  say  nothing 
of  the  garden-ground  occupied  by  Jerusalem  artichokes, 
scarlet-runners,  haricot-beans,  and  ornamental  plants, 
we  may  form  some  idea  of  the  alterations  produced  in 
the  green  world  of  the  east  by  the  discovery  of  the 
other  half  of  the  globe.  There  is  indeed  hardly  a  park, 
or  even  a  cottage-garden  in  Europe,  where  plants  from 

23 


354  Man's   Work  on  the  Farm 

the  west  are  not  now  familiar  objects;  they  are  plenti- 
ful in  China  and  Japan,  and  throughout  the  length  and 
breadth  of  India.  But  still,  though  they  have  con- 
siderably altered  the  appearance  of  our  gardens,  and, 
in  some  districts,  of  our  fields,  the  change  has  been 
mainly  confined  to  these,  the  cultivated  portions  of  the 
soil.  In  the  north,  at  all  events,  American  plants  have 
not  run  wild  in  any  overwhelming  manner,  though  the 
prickly  pear  has  done  so  in  the  south,  and  the  pine- 
apple has  covered  some  parts  of  Borneo  ;  and  it  is  true 
that  the  American  pond-weed  even  put  us  to  consider- 
able expense,  by  choking  our  canals.  The  general 
appearance  of  our  woods,  moors,  wild  hill-sides  and 
'  wastes/  at  all  events,  is  little,  if  at  all,  altered  by  the 
presence  of  strangers;  and  though  potatoes  are  an 
important  crop  in  the  north,  while  maize  and  tobacco 
occupy  a  good  share  of  the  cultivated  ground  in  the 
south,  yet,  except  in  some  few  districts,  it  is  only  a 
share,  and  wheat,  barley,  rye,  oats,  clover,  etc.,  form 
the  chief  part  of  the  crops  of  Europe  now,  as  they  did 
before  Columbus  crossed  the  Atlantic. 

It  is  far  otherwise,  however,  with  that  new  world 
which  he  discovered.  In  many  parts,  European  plants 
have  almost  ousted  the  natives,  and  have  entirely 
altered  the  character  of  the  vegetation.  In  the  south, 
for  instance,  180  miles  of  wild  artichokes  and  clover 
have  sprung  up  since  first  the  continent  was  visited 
by  Europeans.  Growing  entirely  on  their  own  account, 
without  any  other  help  from  man  than  that  of  an 
'assisted  passage,'  they  have  overpowered  whatever 
native  plants  occupied  the  ground  before  them,  and 
are  now  being  themselves  invaded  here  and  there  by 
large  groves  of  wild  apple-trees,  also  European,  planted 


Man's   Work  on  the  Farm  355 

by  pigs  and  cattle.  But  in  the  north,  greater  changes 
than  this  have  taken  place ;  for  miles  —  hundreds, 
thousands  of  square  miles — have  been  brought  under 
cultivation  which  were  never  cultivated  before;  and 
the  whole  of  the  crops  grown  throughout  the  United 
States  are  foreign,  with  the  trifling  exception  of 
Jerusalem  artichokes  and  pumpkins ! 

When  Louisiana  was  settled  by  the  French,  for 
example,  less  than  a  couple  of  hundred  years  ago,  the 
uplands  were  covered  with  magnificent  forests  of  elm, 
ash,  oak,  cherry,  magnolia,  mulberry,  and  wild  grape. 
Whereas  the  greater  part  now,  where  it  has  not  been 
abandoned  as  exhausted,  is  covered  with  cotton — 
cotton  not  of  the  native  species,  but  that  brought  to 
Europe  by  the  Arabs. 

This  is  only  a  sample  of  what  has  occurred  through- 
out the  United  States  and  in  Canada.  For  it  is  a 
curious  fact  that,  useful  as  are  many  of  the  plants 
which  America  has  given  to  Europe,  they  amount  to 
no  more  than  forty-five  species — about  250  species  are 
in  common  cultivation  all  over  the  globe — and  of  these, 
all  but  the  two  already  mentioned  are  natives  of  South 
or  Central  America,  for  the  Indians  of  North  America 
were  chiefly  hunters,  not  agriculturists. 

Potatoes,  it  is  true,  were  brought  to  Europe  from 
Virginia,  but  they  were  strangers  for  all  that,  and  not 
known  in  the  State  until  introduced  by  Europeans, 
who  had  made  their  acquaintance  in  the  south ;  and 
to  make  room  for  them,  as  well  as  for  the  various  kinds 
of  corn,  grasses,  clover,  cotton,  hemp,  flax,  fruit  and 
vegetables,  which  form  the  main  part  of  the  crops  of 
the  United  States  farmer,  native  plants  have  necessarily 
been  turned  out.  They  have  not  been  exterminated, 


356  Mans  Work  on  the  Farm 

but  the  space  they  occupy  has  been  much  circum- 
scribed, and  will  be  limited  more  and  more,  as  more 
land  comes  into  cultivation. 

Coffee  from  Abyssinia,  the  sugar-cane,  peach,  and 
orange  from  Asia,  are  all  extensively  cultivated  in  the 
Western  world,  while  the  two  last  have  run  wild,  and 
form  considerable  groves  in  some  parts;  and  whole 
forests  of  coco-palms  waved  on  the  islands  near 
Panama  within  a  hundred  years  of  their  first  intro- 
duction. All  these  were  valuable  additions  to  the 
vegetable  wealth  of  the  new  world;  but  the  more 
foreigners,  the  fewer  natives.  The  green  things  were 
quite  as  many,  but  they  were  different. 

So  much,  then,  for  the  useful  plants.  It  has  been 
said  that  'no  beautiful  or  useful  organic  species, 
animal  or  vegetable,  becomes  naturalized  in  any 
country  without  the  intervention  of  man,  while  the 
noisome  and  ugly  succeed  in  establishing  themselves 
in  spite  of  him ' — a  sweeping  assertion,  which,  as  re- 
gards the  former  half  of  it,  is  hardly  borne  out  by 
facts.  But  the  second  half  is  undoubtedly  true 
enough. 

Though  we  cannot  consent  to  call  '  noisome  and 
ugly '  the  weeds  which  beautify  the  fields  and  meadows 
of  Europe,  we  must  admit  that  they  have  followed 
man  quite  without  his  invitation,  though  not  without 
his  unconscious  help,  and  that  in  many  cases  he  has 
to  fight  a  sore  battle  with  them,  and  does  not  always 
come  off  conqueror. 

Most  of  our  weeds  have  made  their  way  to  the 
West  by  the  various  ways  already  mentioned,  and 
among  them,  it  must  be  confessed,  some  which  are 
not  only  not  ornamental,  but  most  injurious  to  the 


Mans  Work  on  the  Farm  357 

fields.  So  extremely  troublesome  are  some  of  these, 
of  the  thistle  tribe,  that  laws  are  passed  to  ensure  their 
being  cut  down,  and  fines  are  inflicted,  in  some  parts,  of 
a  dollar  per  plant  if  they  are  allowed  to  ripen  their 
seed ;  while  so  desperate  is  the  battle  felt  to  be,  that, 
in  Manitoba,  persons  who  do  not  cut  them  down 
within  five  days,  after  they  have  been  warned,  are 
fined  •£ i  a  day.  Station-masters  are  held  responsible 
for  the  weeds  on  railway  property;  and  seed-merchants 
convicted  of  selling  seed  containing  any  admixture  of 
wild  oats,  wild  mustard,  or  '  Canada-thistle/  are  fined 
from  -£2  to  £20.  Nevertheless,  in  spite  of  the  war 
waged  against  it,  the  last  of  these  is  a  '  pest '  on  all 
badly  cultivated  farms,  and  renders  some  of  the  country 
roads  of  Ontario  almost  impassable. 

But  now  to  consider  briefly  some  of  the  vegetable 
changes  which  have  taken  place  in  other  parts  of  the 
globe.  The  last  of  these  have  been  due  to  the 
discovery  of  Australasia,  where  all  the  crops  now 
cultivated,  as  well  as  many  which  are  not  cultivated, 
are  foreign  importations  from  Europe,  Asia,  and 
America,  for  Africa  has  supplied  few  emigrants. 

None  of  the  plants  grown  by  the  natives  had  oeen 
sufficiently  improved  to  make  them  worth  cultivating 
by  Europeans ;  and  the  only  useful  plant  which 
Australia  has  given  to  the  rest  of  the  world  is  the 
eucalyptus,  which  seems  already  to  belong  to  the 
Mediterranean  as  much  as  the  olive,  cactus  and  aloe. 

In  Australia,  as  elsewhere,  man  has  had  to  find  out 
by  experience  how  hazardous  it  is  to  bring  colonists 
into  a  new  and  comparatively  unoccupied  land,  unless 
he  is  sure  he  can  control  them.  It  is  not  only  in  the 
matter  of  rabbits  that  he  has  discovered  his  mistake. 


358  Mans  Work  on  the  Farm 

He  had,  to  be  sure,  no  conscious  share  in  bringing 
the  Pampas-artichoke  to  Australia;  for  the  seeds  made 
use  of  his  cattle  and  his  ships  without  consulting  him ; 
but  he  negligently  allowed  the  plant  to  establish  itself. 
He  did  not  eat  its  heads,  or  boil  its  stems,  as  he  might 
have  done  ;  and  it  has  improved  the  opportunity  to 
form  an  impenetrable  belt  along  the  margins  of  the 
creeks  in  many  parts  of  Victoria  and  New  South 
Wales.  But  in  other  cases  man  has  directly  brought 
his  troubles  upon  himself,  though  it  would  be  hard  to 
blame  him ;  for  who,  seeing  the  sweetbriar  for  in- 
stance at  home,  could  possibly  guess  that  it  would 
prove  a  nuisance  abroad  ?  Yet  this  is  just  what  it  has 
done.  It  has  grown  so  rampantly  as  to  make  whole 
regions  in  Tasmania  practically  valueless,  for  the 
expense  and  difficulty  of  clearing  it  away  are  so  great 
that  the  land  has  been  abandoned  and  given  over  to 
the  enemy. 

The  prickly  pear  has  also  proved  an  expensive 
emigrant,  for  it  has  escaped  from  the  gardens  in  which 
it  was  to  have  been  confined,  and  has  taken  possession 
of  extensive  districts,  from  which  it  will  not  easily  be 
dislodged.  This  cactus,  as  well  as  the  Scottish  thistle 
— brought  over  by  a  patriotic  but  misguided  Scot,  who 
has  not  received  the  thanks  of  the  community — has 
been  the  subject  of  special  Acts  of  Parliament,  and  to 
keep  the  two  even  in  check  costs  the  country  many 
thousands  every  year. 

These  and  the  Capeweed,  which  has  nearly  destroyed 
every  natural  pasture  plant  for  miles  round  Melbourne, 
having  sprung  from  seed  thrown  out  on  some  waste 
land — these  are,  perhaps,  the  worst  vegetable  enemies 
of  the  Australian.  But  they  do  not  by  any  means 


Marts   Work  on  the  Farm  359 

exhaust  the  list ;  and  even  the  watercress,  which  is 
humble  enough  at  home,  has  become  so  wildly  luxuriant 
in  some  parts  as  actually  to  dry  up  sluggish  streams 
and  cause  much  inconvenience  to  the  sheep. 

Some  of  the  accidental  colonists,  on  the  other  hand, 
have  turned  out  real  blessings — such,  for  instance,  as  a 
coarse  species  of  grass  which  somehow  found  its  way 
to  Australia  from  India,  as  is  supposed.  In  Arabia,  as 
well  as  in  India,  this  grass  supplies  food  for  cattle  in 
districts  which  would  otherwise  be  desert  and  unin- 
habitable ;  and  it  is  of  incalculable  service  in  the 
warmer  parts  of  Australia,  flourishing  where  other 
fodder-plants  cannot  stand  the  heat,  and  keeping 
luxuriantly  green  the  district  round  Sydney,  which 
before  its  coming  had  been  withered  and  desert-like 
throughout  the  summer  and  autumn. 

Such,  then,  are  some  of  the  more  striking  changes 
which  man  has  made,  intentionally  and  unintentionally, 
in  the  appearance  of  the  green  world.  They  began  as 
soon  as  he  began  to  cultivate  the  soil  and  interfere 
with  the  natural  labourers,  and  they  have  been  going 
on  ever  since  more  and  more  rapidly,  especially  during 
the  last  three  hundred  years.  And  what  we  see  now 
taking  place  in  America  and  Australia  may  serve  to 
remind  us  of  what  has  been  done  in  Europe  ;  for  here, 
too,  the  space  now  occupied  by  fields,  orchards,  gardens, 
as  well  as  by  towns  and  villages,  was  covered  in  bygone 
times  by  a  dense  growth  of  forest  and  underwood  and 
green  things,  of  nature's  planting. 

And  so,  also,  with  the  crops.  If  those  grown  in 
Australia  are  all  foreigners,  so,  too,  are  most  of  those 
grown  in  Europe ;  for,  though  in  many  cases  we  have 


360  Man's  Work  on  the  Farm 

almost  forgotten  the  fact,  it  is  to  Asia  that  the  world  is 
indebted  for  the  most  important  of  its  food-plants. 

But  with  all  that  man  has  done,  and  widely  as  his 
influence  is  felt  beyond  his  own  especial  domains,  he 
has  at  present  taken  but  a  small  portion  of  the  soil 
actually  under  his  own  care ;  and  even  in  that  small 
portion  he  would,  as  we  have  seen,  be  quite  helpless — 
unable  to  produce  even  so  much  as  a  single  crop — 
without  the  constant  help  of  the  many  natural  labourers 
who  are  always  at  work,  some  or  other  of  them,  day 
and  night,  summer  and  winter,  in  every  part  of  the 
*  great  world's  farm.1 


INDEX. 


ABYSSINIA,  41,  356 
Acacia,  6,  98,  306 
Acids,  35,  136 
Africa,  i,  6,  98 

South,  66,  no,  us,  115 
Air,  19,  164,  176 

,,    moisture  in,  19,  125 
Agave,  353 
Albumin,  158 
Aloe,  American,  193,  353 
America,   plants  from,  353-4;  taken 

to.  354-7 
Ant-eaters,  88 
Ants,  82-87,  24X>  306-9 
Apple,  219-20 

„      wild,  276,  354 
Arabs,  349-50 
Arbor-day,  121 
Artichoke,  Jerusalem,  344,  355 ;  wild, 


3,  146,  297,  358 
sh  it 


Ash  in  plants,  16,  140-4, 145 
Asia,  plants  from,  345-52 
Australia,  97,  266,  357 

BALANCE  OF  LIFE,  334-6 

Bananas,  162 

Bark,  91 

Basalt,  20 

Beans,  13,  280 

Beavers,  45 

Bees,  215-22,  227,  230 
„     colours  preferred  by,  225 
„     flowers  shunned  by,  224 
,,     humble,  13,  218,  225,  227,  232 
,,     protection  against,  244 

Beetles,  70,  236,  310,  329,  335 

Bindweed,  52,  233 

Birds,  3x3 


Birds,  destruction  of,  314,  316-17 
„      as  seed-carriers,  261-73 
,,      fertilization  by,  224,  234 

Bison  hollows,  58 

Black  cap,  320 

Black  earth,  61,  62,  134,  146 

Blossom,  size  of,  193-4 
,,       structure  of,  194 

Blossoming,  193 

Bourbon,  Isle  of,  323 

Brazil-nuts,  265,  290 

Breathing,  174 

Buckwheat,  352 

Bulbous  plants,  173,  192 

Burrowing  animals,  63 

Burs,  265-7 

Butterflies,  229,  311 

CABBAGE,  96,  103,  159,  279 
Cactus,  35,  36,  98-9,  in,  353,  358 
Canadian  fleabane,  343 
Carbon,  160,  162,  167,  173-5 

,,        dioxide,  22,  161,  164 
Carnivorous  plants,  149 
Carses,  44 
Catkins,  209 

Caterpillars,  310-11,  320,  321 
Cattle,  influence  of,  276,  292,  294 
Cedar,  red,  272 
Cells,  167-9 
Ceylon,  sand-bars  of,  53 

,,      cinnamon  in,  271 

,,      vine  in,  187 
Cherry,  348 
China,  agriculture  in,  347 

,,      plants  from,  348,  351 

,,      weeds  in,  343 
Chinese  gardeners,  176 


362 


Index 


Cinnamon,  271 

Citron,  351 

Clover,  142, 146,  218,  333,  341,  354-5 

,,      roots,  56 
Coco-nut,  54,  257,  356 
Cockchafer,  325,  328-9 
Colchicum,  192,  206 
Colonists,  285,  296-7 
Colours,  meaning  of,  224-5,  32^»  274 
Composites,  196,  299 
Convolvulus,  53,  233,  345 
Coral-sand,  53 
Cork,  91 
Corn,  345 
Cotton,  353 
Crabs,  69 
Cranesbill,  289 
Cross- fertilization,  204,  206 
Crowding,  250 
Crown-imperial,  224 
Cuckoo,  316 
Cultivation,  effects  of,  338 

„         extent  of,  3 
Currant,  213,  344 
Currents,  256-9 

DADDY  LONGLEGS,  328 
Dahlia,  197,  224 
Dartmoor,  38 
Date-palm,  210,  350 
Decay,  154 
Defences,  240 
Delta,  43 

Desert,  Kalahari,  no,  112-14,  I25. 12& 
,,      Nubia,  121,  187 

Sahara,  6,  118 
Deserts,  2,  5,  6 

,,        vegetation  of,  112,  122 
Djebel  Attakah,  5 
Dolomite  Mountains,  5 
Double  flowers,  197 
Down,  255 
Downs,  39 

Drought,  causes  of,  118-121,  323 
Dust,  47 

„     meteoric,  7 

,f     on  leaves,  176 

„     sirocco,  47 

,,     volcanic,  48 

EGYPT,  41, 120-21 
Enclosure,  effect  of,  271,  294,  339 
Eucalyptus,  97,  112,  357 
European  plants,  285,  298,  354 
Evaporation,  91 

„  prevented,  96 

Evergreens,  95,  186 


FALLOW  FIELDS,  156 

Farm,  meaning  of  word,  4 

Ferments,  154 

Fertilization  by  bees,  215-22 

by  birds,  224,  234 
by  butterflies,  225,  2 
by  flies,  236 
in  bud,  205 
by  moths,  231-3 
self,  204-206 
by  snails,  239 
by  wasps,  235 
by  water,  214 
by  wind,  208-13 

Fig,  247 

Fires,  forest,  143,  293 
,,      prairie,  61 

Fire-weed,  293 

Foliage,  98,  103 
,,       desert,  97 

Food  of  plants,  15,  139,  157 

,,.       ,,        different    values 
158-60 

Forms,  different,  222 

Foxglove,  7,  221,  245 

Frost,  25,  156,  293 

Fruit,  190,  212 
„      -eaters,  273 
,,      ripening  of,  179-181,  185 

Fuchsia,  195,  198 

Fungi,  172 

GASES,  18,  164 

, ,      weight  of,  164 
Germs,  154 
Gipsies,  341,  352 
Glaciers,  27 
Glass  road,  26 
Goats,  7, 119 
Goose-wheat,  260 
Gourds,  in 
Granites,  23,  37 
Grasses,  4,  102,  142,  209,  301 
Grasshoppers,  319,  323 
Growth,  rate  of,  172,  193 
Grubs,  310,  314-15,  319-20 

,,      lawsuits  against,  311 
Gulf  Stream,  184,  259 
Gum-tree,  97 

HAIRS,  100,  305 
Hawks,  270,  334 
Hawthorn,  272 
Heather,  142 
Hedges,  47,  57,  31$ 
Helena,  St.,  119 
Holly,  217,  297 


Index 


363 


Horse-chestnut,  350 
Humming-birds,  234 
Hungary,  dust-storms,  50 

„         floods  in,  46 

„        saltworts  in,  144 

„         sparrows    banished    from, 
326 

ICE-PLANT,  no 

Insects,  numbers  of,  9,  318,  319-22 
Iodine,  140 
Iron,  20,  169 

Italy,  birds  destroyed  in,  316 
„     plants  introduced  into,  346 

JAMAICA,  267,  271, 323 

KALAHARI  DESERT,  112,  114,  128 
Krakatoa,  eruption  of,  48 

LAKE-DWELLERS,  345 

Landes,  57 

Larks,  317 

Lava,  breaking  up  of,  31 

„      lichens  on,  31 
Leaf-green,  169, 172 
„    pores,  93-5,  171 
Leaves,  altered,  157,  196 

„       number  of,  103 

„       office  of,  169 

,,       size  of,  103 
Lichens,  4,  6,  30,  340-41 
Locusts,  275,  310-11,  324 
Locust-tree)  293 
Lupin,  147 

MANGROVES,  54 

Manitoba,  61 

Manuring,  61,  145 

Maple,  109,  294 

Melon,  12,  112,  113,  185,  197,  282, 

290,348 
Mesquite,  HI 


Mineral  matter  in  plants,  17,  61, 140 

Mississippi,  44 

Mistletoe,  272-3 

Mole,  66,  335 

Mongoose,  323 

Monkeys,  264 

Moss,  32, 140 

Moths,  231-2 

Mud,  river,  42,  46,  53 

Mummy-wheat,  282 

NAMES,  CAUTION  AS  TO,  344 
Nettle,  223,  247,  305,  348 


Nile,  42-44, 134 
Nitrates,  151-6 
Nitrogen,  148-52 

,,        compounds  of,  153, 158, 160 
North,  vegetation  of,  188 
Nubia,  desert  of,  121,  187 
Nuthatch,  264 

OAK-FORESTS,  262 

Ohio,  crops  in,  133 

Oleander,  224,  347 

Olives,  346 

Orange,  220,  308,  351 

Orchids,  228,  231,  283-5,  3°7 

Organic  matter  in  soil,  61 

,,  ,,    required  by  plants,  148 

Ovary,  195 

,,      development  of,  213 
Ovules,  195,  199,  206,  212-13,  248 
Owls,  333 
Oxalis,  222 
Oxygen,  19 

PALMS,  193,  210 

Pampas,  3,  4,  64,  146 

Para,  vegetation  at,  8 

Passion-flower,  204,  224,  307 

Peru,  rainless  zone  of,  5 

Phoenicians,  347 

Pigs  as  planters,  276,  292,  355 

Pimento  walks,  271 

Pines,  57,  95,  zoo,  209,  339 

Pistil,  195,  212,  255 

Pitcher-plants,  151,  235 

Plantain,  342 

Poisonous  plants,  302 

Pollen  grains,  197,  200 

„      poisonous,  204,  221 

,,      tubes,  200,  205,  213 

,,      masses,  231 
Potato,  344,  355 

Prickly  pear,  35,  36,  in,  353,  358 
Primrose,  142,  194,  222,  228 
Protection  against  enemies,  240,  243, 

300 
„  ,,      evaporation,  95-100 

RAFFLESIA  ARNOLDI,  194 

Rainfall,  115-23 

Raspberry,  fertilization  of,  219 

,,          seeds,  283 
Rats,  65,  291 
Redstart,  320 
Red  snow,  7,  185 
Rhdne,  45 

Ripening  of  fruit,  179-81,  185 
Riverina,  292 


364  Index 


Rivers,  43,  44,  46,  53 
Rooks,  262,  330 
Romans,  348  9 
Roots,  35.  52,  55,  58,  80,  124 

„     acid  in,  35,  136 

„     hairs  of,  131 

ti      length  of,  131 

,,      effect  of  sun  on,  187 

„     worm -burrows  and,  135 
Rose,  garden,  346 

,,      -trees  and  snow-drifts,  57 
Rushes,  55 

Russia,  61,  62,  134,  144,  146 
Rust,  19 

SAFFRON,  351 
Sahara,  119 
Salt,  143 

„    -worts,  144 
Salts,  137,  153 
Sand-drifts,  51,  57 
Santo  Domingo,  garden  in,  13 
Sap,  92,  107-9 
Saracens,  349 
Scarlet-runners,  13 
Scents,  208,  223,  225,  237-9,  303 
Sea-reed,  55 

,.    -sedge,  55 

„    -water,  16,  140 

„    -weeds,  15 
Sedge,  bristles  of,  268 
Seed,  destruction  of,  286-7 

„     carried  by  animals,  265,  276. 355 

„  „       birds,  260-72 

M  ,.       fish,  275 

„  ..       locusts,  275 

.,  „      water,  256-9 

„  „       wind,  51,  253 

„     eaten,  327 

„     feathered,  255 

„     hooked,  265 

,,     in  mud,  268 

„     nitrogen  in,  160 

„     mystery  of,  277 
Seeds,  hard  coats  of,  272,  283,  293 

,,      quantity  of,  287 

„      self-burying,  289 

„      similarity  of,  279 

,,      size  of,  281 

„      vitality  of,  281 
Seedlings,  destruction  of,  12, 284,  300, 

319 

Seed-vessels,  exploding,  252 
Smell,  sense  of,  241,  303-4 
Snow-drifts,  57 
Soil,  zo,  61-4 

„    colour  of,  185 


Soil,  moisture  in,  126 
,,    warmth  of,  185 
Sparrows,  324-7,  331 
Species  cultivated,  number  of,  4 
Squirrels,  gray,  264 

„        ground,  64 

„        red,  263 

„        tree,  263 

,,        seeds  planted  by,  264,  293 
Stamens,  195 

,,        and  petals,  196 
Starch,  166-7 
Steam,  24 
Stigma,  199 
Strawberry,  218 
Suez  Canal,  120 
Sugar-cane.  351 
Sundew,  150 
Sunflower,  103,  151,  344 
Sunlight,  161,  177 
Swallows,  317,  323 

TEMPERATURE,  177 

,.  changes  of,  26,  181 

tl  effect  of  evaporation 

on,  116,  183 
,,  effect  of  ocean  on, 

184 

„  of  blossoms,  238 

M  of  fruit,  113 

„  of  plants,  113, 175 

,,  of  soil,  185 

Thistles,  146,  297,  303,  331,  357-8 

Thorns,  305-6 

Ticks,  322 

Titmouse,  321 

Tobacco  plants,  126 

Tokay,  143 

Transpiration,  93,  106 

Trees,  destruction  of,  56,  115,  118 
,,      effect  of,  on  air  and  soil,  57, 
103, 118-21,  338-9,  355 

Tulip,  350 

Turkeys  and  hedges,  272 

Turkestan,  birds  in,  324 

Turks,  350 

VALLISNERIA,  214 
Vanilla,  298 
Venus's  fly-trap,  149 
Vine,  143,  180,  187 
Vineyards,  143,  159 
Violet,  205,  206 

WARMTH  OF  BLOSSOMS,  238 

„         need  of,  217 
Wasps,  235-6,  335 


Index 


365 


Water,  6,  16 

„      absorbed  by  soil,  125 

,,      given  up  by  plants,  102,  104, 
116 

„      in  plants,  90 

„      movement  of,  in  plants,  108 

.,      in  soil,  125,  128 
Water-lily,  256     ' 

,,      -pink,  256 
Wax,  93,  96 


Weeds  286,341-3,348,356,358 

Wind,  birds  carried  by,  269 
„      dust  carried  by,  46,  51 
,,      fertilization  by,  208-12 
,,      seeds  carried  by,  253 

Wireworm,  329-30 

Worms,  73-83,  i35 

Wren,  321 

YELLOW  EARTH,  145 


THE   END. 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


MAY  »4  19*4 


30m-6,'14 


v 


